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. 2022 Dec 15;17(12):e0278318. doi: 10.1371/journal.pone.0278318

Factors influencing the timely completion of construction projects in Sri Lanka

Nadeesha Abeysinghe 1, Ruwan Jayathilaka 2,*
Editor: Anu Sayal3
PMCID: PMC9754246  PMID: 36520802

Abstract

Timely completion is a crucial factor for the success of a construction project, especially in the Sri Lankan context. This study aims to identify the most influential factors that affect the timely completion of construction projects in Sri Lanka. Thirty-nine factors were identified through a comprehensive literature review and experts’ opinions. A questionnaire incorporating the 39 project delay factors was distributed among 163 Civil Engineers, and responses were obtained. Random sampling method was adopted to select the sample. The Relative Importance Index (RII) analysed and ranked the project delay factors. The top ranked significant project delay factors were identified as shortage of skilled subcontractors/suppliers, shortage of labourers (Skilled, semi-skilled, unskilled), financial difficulties of contractors, delay in delivering materials to the site, and Covid-19 pandemic situation. According to the main three respondent types, i.e., clients/owners, contractors and consultants, the contractor related factors was the key group among others that delay a construction project. The scientific value of the study includes assisting the Sri Lankan construction industry to identify the factors affecting the timely completion of construction projects, and developing mitigation methods and strategies. Also, the stakeholders could duly schedule the construction work by identifying areas that need more attention. The contribution of this study would assist stakeholders to adopt a proactive approach by identifying mistakes on their part and minimising potential issues that lead to construction project delays in Sri Lanka.

Introduction

The construction industry is a key contributor to the Sri Lankan economy. Currently, the construction industry accounts for 7.1% of the gross domestic product (GDP) in Sri Lanka. Also, over 600,000 labourers are currently employed countrywide construction sites in Sri Lanka. Annually, the construction sector generates approximately LKR 4.2 billion of revenue [1].

Due to the covid-19 pandemic, every sector had its share of downfall. Nevertheless, with the slow-paced economic recovery, the construction industry too is picking up slowly but steadily. At the time of writing, many construction projects have recommenced work and are rising slowly. Many massive infrastructure projects are currently under development, such as the Port City Development Project, the extension of the Southern Expressway from Matara to Hambanthota, the Central Expressway Project etc. Apart from these, the country has many ongoing major housing, residential and commercial projects. Under these circumstances, the Sri Lankan construction industry is expected to undergo massive growth within the next 15 to 20 years [2].

The nature of the construction industry can be considered as uncertain. Construction projects differ from each other depending on the project size, project objectives, project duration, etc. Every project is unique on its own and no project has the same characteristics. Even though the construction projects nowadays use advanced and new project management theories and technologies, the delay in the completion of projects cannot be mitigated [3].

The time deviation of a construction project can be defined as the difference between specified project duration and the real project duration. There can be three types of time deviations in a construction project. Firstly, is a negative deviation, where the real duration is less than the specified duration. Secondly, there is the no particular deviation type, where the specified duration and the real duration are the same. Thirdly, is the positive deviation, where the real duration is greater than the specified duration. This positive deviation is also known as the time overrun, where the delays in the project completions occur. When the delay period is long, consequently the effects will also be greater/significant, which can exert a negative impact on the project. For the successful completion of a project, cost, quality as well as time, should be properly utilised [4].

Therefore, timely completion is one of the crucial factors for the success of any construction project. At the initial stage, a project should be well planned to be delivered within the specified time range. In Sri Lanka, it is common for most construction projects to get delayed for various reasons [5]. Construction project activities revolve around the client, contractor, and consultant, who are its main stakeholders. Therefore, the key stakeholders should properly plan, schedule, and monitor each phase and every key activity of the project throughout the process. This is because when a construction project is delayed, the parties mentioned above will also get severely affected [6]. The client will lose their revenue as the project could not be available for business. When the project gets delayed, it means that contractors, too require a longer time duration than initially estimated. Accordingly, the contractors will face financial difficulties, additional charges, penalties for time overrun etc., to pay wages for the labourers, materials, and equipment for an extended time. As such, costs will push up for the remaining activities while revenue will remain almost unchanged in line with estimates. Further, delayed projects constrain securing new construction projects as well as losing the earning potential. In other words, a delayed project means more expenses, narrow profit margins, loss of credibility and reputation, and loss of future revenue [7].

Various factors influence a construction project. Resource-related issues are also causing major problems for any construction project. Resources include human resource, materials, equipment, etc [8]. The procurement process is a vital part of the project that should be duly completed within the specified project duration. The external environment can adversely affect project completion. The external stakeholders, such as the government, regulatory bodies, the public, etc., can arouse issues for project completion in numerous ways. These include changes in regulations, and inefficient handling of approvals by govt. authorities [9]. Therefore, that time overruns can occur due to various factors. This study will attempt to identify the most crucial factors that can influence a construction project duration in Sri Lanka.

The objective of this study is to identify the most significant factors that can affect the timely completion of a construction project in Sri Lanka. The scientific value of the study can be elaborated by identifying the difference between the present study and similar studies which have been conducted previously on the Sri Lankan construction industry. This can be explained in four ways. Firstly, the study has analysed the responses given by the main three stakeholders of a construction project, namely, client/owner, contractor, and consultant. Based on their opinions the most influential project delay factors were identified with respect to each type of stakeholder. It is a must to understand perspectives of each stakeholder on construction project delays, and in reality, how each party play the blame game.

Secondly, the study was done based on factors related to client/owner, contractor, consultant, resources, and external factors. Based on the results, the most important factor in each group was identified. This will be useful for the stakeholders to identify which factors they should pay more attention to, and factors to be considered when setting priorities under each category. Thirdly, the most influential group of factors, which could affect the timely completion of a construction project was identified. Since the construction sector plays a major role in contributing to the country’s economy, the findings of the study help policymakers gain valuable insights into construction project delays.

Finally, the study will enable to set up a platform for Civil Engineers in Sri Lanka for knowledge sharing and collaboration with experts and construction players. This type of approach will assist them in sharing their opinion and addressing existing and potential issues etc., regarding construction project delays in Sri Lanka.

Literature review

Many studies have been conducted in various parts of the world to identify the factors causing time and cost overruns in construction projects. Some studies have ranked the factors according to their effectiveness on the project duration, while others have suggested mitigation methods to overcome delays. Several publications were critically analysed to understand better and identify different perspectives on how past researchers have addressed the selected research area for this study. These findings will be useful in decision making to choose the most suitable research path and identify the research gap. Fig 1 shows how the literature search was carried out in a step-by-step approach.

Fig 1. Literature search flow diagram.

Fig 1

Source: Based on authors’ observations.

The literature review for this study consists of 40 published articles identified using a comprehensive literature search. Authors referred to reputed search databases such as Emerald insight, Science direct, Taylor & Francis online, Wiley online and Springer for this purpose. Most studies focus on analysing the major project delay factors based on the different stakeholders’ perspectives. However, the critical project delay factors did not have a noticeable relationship among other continents. Various financial situations, availability of resources, government regulations etc., have led to the difference in delay factors between continents [10]. Therefore, to provide a better understanding, these articles were recategorised into three based on the continent where the authors have addressed the research problem. Therefore, the articles were categorised as factors affecting the project delivery in countries in Asian, African and European regions.

Factors affecting construction project completion in Asian countries

In Malaysia, Alaghbari, Razali A. Kadir [11] found that the most effective factors related to project delay have been linked with the contractor. The study was conducted to identify the major causes of delay in building system construction projects in Malaysia, where the data were collected from several construction parties. Here, the most effective factors related to project delay have been occurred by the contractor, and among these, financial problems faced by the contractor play a major role in delaying the construction projects. Zailani, Ariffin [12] found the relationship between possible causes of delay and construction project performance. Out of the 1,322 registered construction project companies in Malaysia, data were collected from 204 companies. The results showed that factors related to coordination, resources and environment were the most effective in minimising delays. The study also suggested that delays could be mitigated by supplier development as well as the project flexibility and visibility. In another research conducted in Malaysia, Yap, Goay [13] found that the constant design changes by the client during construction, lack of experienced supervisors and subcontractors, financial difficulties of contractors and poor scheduling and planning led to the construction project delays. Enshassi, Al‐Najjar [14] found that the material-related factors and the labour strikes affected the construction project delays in the Gaza strip. This study was conducted in 2009 to identify the key variables causing construction project delays from the perspective of contractors, consultants, and clients. Mahamid [15] developed a risk matrix which depicts the possible time overrun factors in Palestine. This study was limited to road construction projects in the West Bank of Palestine, in which, the factors reflected only from the client’s point of view. The risk matrix developed in this study could be used to identify the impact of each delay factor and its probability of occurrence. Gardezi, Manarvi [6] conducted a study in Pakistan in which the construction project delay factors were ranked using the Relative Importance Index (RII). It was found that the external factors related to a construction project could highly affect the timely delivery of the project.

In 2016, a study on construction project delay factors in Gulf Countries Construction industry, Elawi, Algahtany [16] intended to find the construction parties responsible for each delaying factor. The results suggested that the most effective project delaying factor was land acquisition and often, construction project delays occurred on the client’s part. Alsuliman [17] researched factor analysis, where the results developed an equation to calculate the actual project duration. This was useful and practical for the Saudi Arabian government to take necessary measures to mitigate public construction project delays. Assaf, Hassanain [18], proved that changes in orders given by clients during the construction, contractor delays and design errors were the most severe project delay factors in the Eastern Province of Saudi Arabia.

In a study conducted in Jordan, Al-Hazim, Salem [19] intended to identify the time overrun factors in public infrastructure projects in Jordan. The study conducted using final reports obtained from 40 infrastructure projects completed between 2000 and 2008 revealed that unfavourable site conditions and weather conditions were the most severe project delay factors. In 2019, another research investigated the delay factors in public construction projects in Jordan. It is noteworthy that the clients and consultants in Jordan were concerned about the delays that occurred by themselves, while the contractors were more concerned about the delays that occurred by the clients Ahmad, Ayoush [20].

In Cambodia, Durdyev, Omarov [8] identified the time overrun factors in residential building construction projects in the country. The factors were ranked according to their importance where material shortage, unrealistic project durations and the lack of skilled labour were the most severe factors to delay the residential building projects. Mpofu, Ochieng [7] claimed that unrealistic project durations and decreased labour productivity have affected the timely completion of construction projects in the United Arab Emirates. It was suggested that all construction parties, including client, consultant and contractor should reorganise their working patterns to successfully complete a construction project. In Iran, a model was developed by Parchami Jalal and Shoar [21] to identify the most effective delaying factor for construction project completion. Here, the factors related to client were the most effective while the external factors were the least effective. Shahsavand, Marefat [22] revealed that the main delay factors in construction projects in Iran were caused by contractors, labourers, clients, and equipment. The relationship between the project delay factors in Iran was analysed by Jahangoshai Rezaee, Yousefi [23]. It was identified that the technical faults during construction and unrealistic workload estimation were the main causes of construction project delays in Iran.

Wang, Ford [24] identified the primary causes of project delays in construction projects in China as payment delays, poor performance by subcontractors and communication problems. In a similar study, Prasad, Vasugi [25] claimed that delay in settlement claims and the financial difficulties of contractors and clients were the most significant delay factors in India. No difference was reported between the delay factors caused in design-build projects and design bid-build projects. Hoque, Safayet [10] confirmed that payment delays and errors during construction were the most significant delay factors in Bangladesh. Although ranked based on their importance, the effect of delay factors on the overall project duration was not analysed.

In Sri Lanka, Santoso and Gallage [5] identified that the contractor-related factors were the most influential factors in delaying large construction projects. The sample size taken for this study was relatively small compared to many construction companies in Sri Lanka.

Factors affecting the construction project completion in African countries

In 2014, a study was conducted in Egypt to examine the construction project delay factors, where poor planning and scheduling and unfavourable soil conditions were the most critical delay factors [26]. In another study by Aziz and Abdel-Hakam [9], contractor-related factors were the most influential factors in Egypt. Some scholars developed models and frameworks on factors concerning construction project delays. In 2020, El-Rasas and Marzouk [27] analysed the causes of residential construction project delays and developed a fuzzy model to determine the probability of delay. Elhusseiny, Nosair [28] developed a systemic processing framework in which the most influential delay factors for Egyptian construction projects were slow decision making, changes in the scope of work and payment delays.

Amoatey, Rolf [29] found that the factors related to financing affect the completion of the public housing construction industry in Ghana. The following year, 86.6% of construction projects in Ghana experienced delays in completion. The samples were obtained only from public school projects. In 2017, the projects related to the education sector in Ghana were analysed. In this study, Famiyeh, Amoatey [30] identified financial problems as well as unrealistic project durations as the most effective delay factors in Ghana. Asiedu & Gyadu-Asiedu, 2019 developed a baseline model to analyse the time overrun of construction projects in Ghana, which was more effective in predicting time overrun than using a multiple regression model. This study also focused on public-school projects using data obtained from the school construction projects completed between 2010 and 2013.

In a South African-based study, Mukuka, Aigbavboa [31], the construction project delay adversely affects the construction parties on a personal level and also the construction company’s reputation. In 2017, corruption, lack of resources, increased material prices and poor site management were the typical causes of delay in construction projects in Ethiopia [32]. Abebe, Germew [33] used Pareto analysis to analyse the delay factors in which lack of utilities and finance-related factors were the main delay causes. The drawback of this study was that the sample size was smaller when compared with the previous study conducted in Ethiopia.

In Nigeria, the quality control of the construction project, financial problems, unfavourable site conditions and fluctuation of material prices were the main causes of delay [34]. Fashina, Omar [35] found that the contractor-related factors are the most effective in delaying the road and building projects in Hargeisa. The study on both public and private construction projects enhanced the significance of the study. Although Mwamvani, Amoah [36]’s quantitative study suggested methods for construction project delays, it was limited to a single organisation in Malawi, hence the findings could not be generalised.

Factors affecting the construction project completion in European countries

Agyekum-Mensah and Knight [37] analysed the construction project delays in the United Kingdom using a qualitative method. The study revealed that poor planning and management, and poor communication and resource management were the most influential delay factors. In 2018, Zidane and Andersen [38] analysed the major Norwegian construction projects, where constant design changes, payment delays, poor site management, and financial problems were the main causes of delay. This study included the participation of 202 respondents from the construction industry. Arantes and Ferreira [39] used factor analysis to find the causes of delays in construction projects in Portugal. Poor planning, consultant performance and poor site management were the most influential delay factors. The sample size was relatively small (94) compared to the population size 2,100. In Denmark, Lindhard, Neve [40] claimed that the construction design and connecting workers and labour force were the most effective delay factors. The study only focused on resource-related factors.

According to the literature, the focus of many past studies was to analyse the factors affecting the timely completion of construction projects. These studies were sometimes conducted only within a specific type of construction project, such as road, building, infrastructure, etc. Also, some studies analysed either public construction projects or private construction projects and in some countries, the study scope was limited to certain areas. Therefore, for comprehensiveness and to fill the research gap, the present study has included every type of construction project, not limiting to projects in some regions of the country. Most of the past studies used the RII to rank the delay factors, as it was accepted as an accurate method to calculate the importance of each factor. Therefore, RII has been used to rank the project delay factors in the present study. Furthermore, the delay factors were analysed based on the type of respondents and the group of factors. The major group of factors that could affect the timely completion of a construction project was also identified.

The subsequent sections of this paper outline the methodology followed by study results, conclusion, and finally reaching the recommendation and policy implications.

Methodology

This section presents the methods and techniques used for data collection and analysis. Fig 2 depicts the flowchart of the research process used for the study.

Fig 2. Flowchart of the research process.

Fig 2

Source: Based on authors’ observations.

Questionnaire design

As the research strategy, survey strategy was adopted for the study where a questionnaire was developed in which the project delay factors were included. The respondents were able to rank each factor according to their significance, with the use of a questionnaire. The questionnaire was developed using 39 project delay factors, which can affect the timely completion of a construction project in Sri Lanka. These factors were identified through a critical literature review and from experts’ opinion. Ten experts were consulted for this purpose. Four authors who have conducted the same type of research studies in the past few years, were contacted to identify the global impact [5, 13, 35, 39]. Six Civil Engineers from the Sri Lankan construction Industry were contacted to identify the national impact.

The demographic data of the respondents were collected under general information at the beginning of the questionnaire, while the rest of the content was divided into five sections. These five sections consisted of eight client/owner related delay factors, followed by eight contractor related delay factors, eight consultant related delay factors, eight resource related delay factors and finally seven general external delay factors, which include soil conditions, weather conditions, government regulations etc. A five-point likert scale was used to collect data for each delay factor which ranged from 1 (Very low significance) to 5 (Very high significance). The questionnaire with the finalised project delay factors is in the S1 Appendix.

Data collection

The questionnaire was distributed among Civil Engineers via electronic mail and manually. Qualified Civil Engineers were selected as the population, since they are engaged in the construction work under all three stakeholder groups namely, client/owner, consultant and contractor. The list of qualified Civil Engineers was obtained through the Construction Industry Development Authority (CIDA) website. A pilot study was carried out by distributing the questionnaire among 10 Civil Engineers. Then, the final questionnaire was distributed to 1,416 respondents selected using a random sampling method from 2,716 Civil Engineers included in the list. One hundred sixty-three responses were collected, of which, 28.8% were from clients/owners, 28.2% were from contractors, 39.9% were from consultants and 3.1% were from other respondents (Civil Engineers who are currently retired or engaged in other work). The data file is presented in the S2 Appendix.

Data analysis

According to Kometa, Olomolaiye [41], RII method was used to determine the importance of each delay factor. The data collected through the questionnaire were used to calculate the RII, mean value and standard deviation for each project delay factor. The following Eq 1 was used to calculate the RII.

RII=i=15wxA×N (1)

where,

RII = Relative Importance Index

A = 5 (Highest weight)

N = Total count of respondents

w = 1 to 5 (weights given to each factor by each respondent)

x = frequency of responses given to each factor

Weights were assigned to each factor by each respondent (1 = Very low significance, 2 = Low significance, 3 = Average significance, 4 = High significance, 5 = Very high significance) were multiplied by the frequency of responses given to each factor, and the total sum of those two values was calculated. The result was divided by the multiplication of the highest weight (5) and the total count of respondents. The ranking of the delay factors was done using the RII. Overall rankings were calculated by combining the responses given by all the respondents.

The responses collected through the open-ended questions included in the questionnaire were analysed using an online word cloud generator for visualisation. The most commonly used word by the respondents is the one which appears to be the largest within the cloud.

Variable analysis and validity of the questionnaire

The internal consistency of the factors was analysed using Cronbach’s alpha coefficient [42]. The pilot study, which consisted of 10 responses, produced a coefficient of 0.9157. The coefficient for the present study, which consisted of 163 responses was found to be 0.9505. According to Gliem and Gliem [43], if Cronbach’s alpha has a value equal to or greater than 0.9, then the internal consistency of the factors can be considered excellent. Therefore, the internal consistency of the collected data was excellent.

Results and discussion

Demographic characteristics

The demographic characteristics of 163 respondents are shown in Table 1.

Table 1. Demographic characteristics of the respondents.

Demographic Characteristics Percentage (%)
Gender based
    Male 82.8
    Female 17.2
Age based
    20–29 years 28.2
    30–39 years 12.9
    40 years and above 58.9
Highest educational qualification based
    Certificate level 0
    Diploma 0.6
    Bachelor’s degree 42.3
    Master’s degree 55.2
    PhD 1.2
    Other 0.6
Work experience based
    Below 5 years 27
    5 to 9 years 1.8
    10 to 19 years 24.5
    20 years and above 46.6
Type of organisation
    Road construction 26.4
    Residential building construction 11
    Commercial building construction 17.2
    Infrastructure construction 28.8
    Water supply/Drainage/Irrigation 6.7
    Other 9.8
Type of respondent
    Client/Owner 28.8
    Contractor 28.2
    Consultant 39.9
    Other 3.1

Source: Authors’ calculations.

According to Table 1, most respondents (82.8%) were male. Among these, 58.9% of the respondents were above 40 years, 55.2% of the respondents had a Master’s degree, while 42.3% had a Bachelor’s degree as their highest educational qualification. The majority of the respondents (46.6%) had work experience of more than 20 years in the Civil Engineering field. Based on the type of organisation, 28.8% of the respondents were employed at infrastructure construction projects, while 26.4% were employed at road construction projects. In terms of percentages, clients, contractors, and consultants responded to the questionnaire at 28.8%, 28.2% and 39.9%, respectively.

Overall ranking

The 39 factors were ranked according to their overall RII. The mean value, standard deviation value, calculated RII and the overall rank for each delay factor are shown in Table 2. The following values are calculated and presented in Sheet 1 in S2 Appendix.

Table 2. Mean value, standard deviation, RII and overall rank of each factor.

Types of delay factors Mean SD RII Rank
Client/Owner-related factors
Q1 Changes in design by the client during construction. 3.4785 1.1240 0.6957 18
Q2 Slowness of client’s decision-making. 3.6687 1.0946 0.7337 13
Q3 Unreasonable project duration given by the client. 3.4663 1.1509 0.6933 21
Q4 Delay in settling contractor claims by the client. 3.5951 1.0402 0.7190 14
Q5 Financial difficulties of the client. 3.7239 1.2033 0.7448 12
Q6 Delay in design approvals. 3.5951 1.1687 0.7190 14
Q7 Poor communication with contracting parties. 3.3067 1.1074 0.6613 29
Q8 Errors in design and specifications. 3.2331 1.2648 0.6466 32
Contractor related factors
Q9 Poor planning and scheduling. 3.9448 1.0438 0.7890 6
Q10 Shortage of skilled subcontractors/suppliers. 4.1472 0.8835 0.8294 1
Q11 Financial difficulties of contractors. 4.1166 0.8635 0.8233 3
Q12 Disagreements between the contractor and other parties. 3.3620 0.9351 0.6724 27
Q13 Poor site management, monitoring, and control. 3.8712 1.0550 0.7742 9
Q14 Errors during construction. 3.2270 1.1016 0.6454 34
Q15 Underestimating the project duration. 3.4724 1.0733 0.6945 20
Q16 Regular changes of subcontractor’s staff. 3.4785 1.0443 0.6957 18
Consultant related factors
Q17 Delay in inspections and completed work approvals. 3.2331 1.0633 0.6466 32
Q18 Delay in material and payment approval. 3.4969 1.1242 0.6994 17
Q19 Errors in contract documents. 3.0614 1.0523 0.6123 36
Q20 Constant design changes by the consultant 3.3681 1.2860 0.6736 26
Q21 Delay in preparing and approving drawings and design documents. 3.4479 1.1502 0.6896 22
Q22 Lack of experienced consultants. 3.3129 1.2096 0.6626 28
Q23 Errors in design documents. 3.1963 1.1159 0.6393 35
Q24 Poor coordination and communication. 3.3865 1.1776 0.6773 25
Resource related factors
Q25 Shortage of labourers. (Skilled, semi-skilled, unskilled) 4.1227 0.9924 0.8245 2
Q26 Delay of delivering materials to the site. 4.0491 0.9545 0.8098 4
Q27 Poor material handling at the site. 3.4294 1.0539 0.6859 23
Q28 Low productivity of labourers. 3.7423 1.0036 0.7485 11
Q29 Fluctuation of material prices in the market. 3.9448 1.0497 0.7890 6
Q30 Inadequate numbers of equipment. 3.9141 0.9054 0.7828 8
Q31 Failure of equipment. 3.5092 1.0679 0.7018 16
Q32 Personal disagreements between labourers. 2.7055 1.0360 0.5411 37
External factors
Q33 Delay in obtaining permissions/approvals from government. 3.7791 1.0484 0.7558 10
Q34 Unknown subsurface conditions. (Soil condition, water table etc.) 3.4294 0.9874 0.6859 23
Q35 Bad weather conditions. 3.2638 0.9927 0.6528 30
Q36 Accidents during construction. 2.5215 1.0849 0.5043 39
Q37 Changes in laws and regulations from the government. 2.6564 1.1297 0.5313 38
Q38 Delay in utility services. (Electricity, water etc.) 3.2454 1.1552 0.6491 31
Q39 Covid-19 pandemic situation 3.9509 0.9349 0.7902 5

Source: Authors’ calculations.

The most significant delay factor was the shortage of skilled subcontractors/suppliers (RII = 0.8294), which fell under contractor-related factors. This result alligned with the results obtained by Yap, Goay (11) and Wang, Ford (22). Shortage of labourers (Skilled, semi-skilled, unskilled) was the second most significant factor (RII = 0.8245) categorised under resource-related factors. This result can be further confirmed by the results obtained by Durdyev, Omarov (6) who conducted a study in Cambodia to identify the time overrun factors in residential building construction projects in the country. These factors seem realistic in the construction industry as most subcontracts/suppliers and labourers are not skilled. The third highest ranked factor was the financial difficulties of contractors (RII = 0.8233), another contractor-related factor. In Malaysia, two research studies (9), (11) confirmed that the financial difficulties of the contractor play a major role in delaying construction projects, while Prasad, Vasugi (23) have also received the same result in the research they conducted in India. Also, delay in delivering materials to the site was the fourth highest ranked delay factor (RII = 0.8098), which was a resource-related factor. Fig 3 shows the graphical depiction of the relationship between the 39 factors and their overall RII.

Fig 3. RII vs causes of delay.

Fig 3

Source: Authors’ illustration.

Ranking based on the type of respondent

According to the type of respondents, the factors considered in the study do not affect the timely completion of a construction project in the same manner. This means responses are rather subjective. Therefore, it is crucial to identify how different respondents have expressed their unique opinions regarding the delay factors. Table 3 shows the mean value, standard deviation value and the calculated RII for each factor, based on the three main types of respondents, namely, client/owner, contractor, and consultant. The calculation of the following values is presented in Sheets 2,3 and 4 in the S2 Appendix.

Table 3. Mean value, standard deviation, RII and rank of each factor based on the type of respondent.

No Client/Owner Contractor Consultant
Mean SD RII Rank Mean SD RII Rank Mean SD RII Rank
Q1 3.1915 1.1912 0.6383 30 3.7391 1.2006 0.7478 16 3.4615 1.0012 0.6923 19
Q2 3.2979 1.3008 0.6596 23 3.9348 0.9522 0.7870 8 3.7385 0.9886 0.7477 12
Q3 3.0213 1.2596 0.6043 34 3.6957 0.9397 0.7391 17 3.5846 1.1577 0.7169 15
Q4 3.4894 1.1396 0.6979 14 3.5435 1.0895 0.7087 21 3.6462 0.9426 0.7292 14
Q5 3.5319 1.2132 0.7064 12 3.6739 1.2121 0.7348 19 3.8615 1.1842 0.7723 7
Q6 3.4255 1.2810 0.6851 15 3.7826 1.0937 0.7565 12 3.5385 1.1467 0.7077 16
Q7 3.1915 1.3292 0.6383 30 3.4130 1.0868 0.6826 27 3.2923 0.9474 0.6585 27
Q8 3.0000 1.3831 0.6000 35 3.3478 1.0795 0.6696 31 3.2769 1.3051 0.6554 29
Q9 3.9362 1.0715 0.7872 6 4.0652 0.9978 0.8130 4 3.8769 1.0681 0.7754 6
Q10 4.1702 0.9628 0.8340 2 4.2174 0.9869 0.8435 1 4.1385 0.7474 0.8277 2
Q11 4.1915 0.8246 0.8383 1 3.9565 1.0532 0.7913 7 4.1538 0.7548 0.8308 1
Q12 3.3830 0.9453 0.6766 18 3.3478 0.8748 0.6696 31 3.2923 0.9638 0.6585 27
Q13 4.0213 1.0932 0.8043 4 3.7609 1.1583 0.7522 14 3.8615 0.9663 0.7723 7
Q14 3.2128 1.1409 0.6426 27 3.3043 1.0513 0.6609 34 3.1692 1.1260 0.6338 32
Q15 3.2979 1.1963 0.6596 23 3.5435 1.0895 0.7087 21 3.5231 0.9860 0.7046 17
Q16 3.5106 1.1396 0.7021 13 3.4783 1.0053 0.6957 24 3.4769 1.0017 0.6954 18
Q17 3.1915 1.1159 0.6383 30 3.4783 1.0486 0.6957 24 3.0615 0.9663 0.6123 36
Q18 3.3830 1.0745 0.6766 18 3.8043 1.0246 0.7609 11 3.3231 1.1471 0.6646 24
Q19 2.7660 1.0046 0.5532 36 3.1957 1.1474 0.6391 36 3.1538 0.9558 0.6308 35
Q20 3.2128 1.3821 0.6426 27 3.6739 1.2121 0.7348 19 3.2462 1.2504 0.6492 31
Q21 3.3404 1.2385 0.6681 22 3.6957 1.0300 0.7391 17 3.3231 1.1740 0.6646 24
Q22 3.2553 1.2592 0.6511 25 3.3913 1.1250 0.6783 29 3.3077 1.2365 0.6615 26
Q23 3.0638 1.0916 0.6128 33 3.3696 0.9512 0.6739 30 3.1692 1.2320 0.6338 32
Q24 3.4043 1.2452 0.6809 16 3.3261 1.0761 0.6652 33 3.4154 1.1976 0.6831 20
Q25 4.0426 1.1221 0.8085 3 4.1739 1.0812 0.8348 2 4.1231 0.8387 0.8246 3
Q26 3.9787 0.9888 0.7957 5 4.0870 1.0072 0.8174 3 4.0308 0.9009 0.8062 5
Q27 3.3617 1.1502 0.6723 21 3.4130 1.0662 0.6826 27 3.4154 0.9665 0.6831 20
Q28 3.6596 1.1088 0.7319 11 3.8696 0.9800 0.7739 9 3.7077 0.9308 0.7415 13
Q29 3.9362 1.1113 0.7872 6 4.0435 1.0101 0.8087 6 3.8615 1.0588 0.7723 7
Q30 3.8723 0.9235 0.7745 8 4.0652 0.8794 0.8130 4 3.8462 0.9054 0.7692 11
Q31 3.3830 1.0945 0.6766 18 3.7826 1.0091 0.7565 12 3.3846 1.0708 0.6769 22
Q32 2.5957 1.1546 0.5191 37 2.7609 0.9472 0.5522 37 2.6769 1.0017 0.5354 38
Q33 3.7021 1.1405 0.7404 10 3.7609 0.9930 0.7522 14 3.8615 0.9823 0.7723 7
Q34 3.4043 0.9704 0.6809 16 3.5217 1.0053 0.7043 23 3.3846 0.9633 0.6769 22
Q35 3.2128 0.9766 0.6426 27 3.4348 1.1861 0.6870 26 3.1692 0.8398 0.6338 32
Q36 2.4894 1.1772 0.4979 38 2.5870 1.1071 0.5174 39 2.5077 1.0019 0.5015 39
Q37 2.4681 1.1951 0.4936 39 2.7391 1.0839 0.5478 38 2.7077 1.0857 0.5415 37
Q38 3.2340 1.1461 0.6468 26 3.2826 1.1863 0.6565 35 3.2615 1.1079 0.6523 30
Q39 3.8723 1.0346 0.7745 8 3.8261 0.9731 0.7652 10 4.1077 0.8315 0.8215 4

Source: Authors’ calculations.

Table 4 shows the top ten ranked delay factors for each group of respondents.

Table 4. Top ranked delay factors for each group of respondents.

Client/owner Contractor Consultant Rank
Financial difficulties of contractors Shortage of skilled subcontractors/suppliers Financial difficulties of contractors 1
Shortage of skilled subcontractors/suppliers Shortage of labourers. (Skilled, semi-skilled, unskilled) Shortage of skilled subcontractors/suppliers 2
Shortage of labourers (Skilled, semi-skilled, unskilled) Delay in delivering materials to the site Shortage of labourers (Skilled, semi-skilled, unskilled) 3
Poor site management, monitoring, and control Poor planning and scheduling Covid-19 pandemic situation 4
Delay in delivering materials to the site Inadequate numbers of equipment Delay in delivering materials to the site 5
Poor planning and scheduling Fluctuation of material prices in the market Poor planning and scheduling 6
Fluctuation of material prices in the market Financial difficulties of contractors Financial difficulties of client 7
Inadequate numbers of equipment Slowness of the client’s decision-making Poor site management, monitoring, and control 8
Covid-19 pandemic situation Low productivity of labourers Fluctuation of material prices in the market 9
Delay in obtaining permissions/approvals from government Covid-19 pandemic situation Delay in obtaining permissions/approvals from government 10

Source: Authors’ calculations.

According to both clients/owners and consultants, the most significant factor was the financial difficulties of contractors. As noted previously, the shortage of skilled subcontractors/suppliers was the most significant factor according to the contractors, while clients/owners and consultants identified it as the second most significant factor.

According to the contractors, the second high ranked delay factor was the shortage of labourers (Skilled, semi-skilled, unskilled). The clients/owners and consultants ranked this factor the third most significant one. From the contractors’ perspective, the third highest ranked delay factor was the delay in delivering materials to the site. Notably, the clients/owners and consultants had nearly the same perspective on the delay factors.

Ranking of factors in each group of factors

The thirty-nine factors were analysed to find out which factors would be the most significant delay factors in each group. Therefore, the factors were ranked based on their overall RII, within each group of factors.

Client/owner-related factors

Table 5 shows the calculated RII and the ranking for eight factors categorised under client/owner-related factors.

Table 5. RII and ranking of client/owner-related factors.
Delay factors RII Rank
Q1 Changes in design by the client during construction. 0.6957 5
Q2 Slowness of the client’s decision-making. 0.7337 2
Q3 Unreasonable project duration given by the client. 0.6933 6
Q4 Delay in settling contractor claims by the client. 0.7190 3
Q5 Financial difficulties of the client. 0.7448 1
Q6 Delay in design approvals. 0.7190 3
Q7 Poor communication with contracting parties. 0.6613 7
Q8 Errors in design and specifications. 0.6466 8

Source: Authors’ calculations.

Financial difficulties of the client were identified as the most significant factor in this group. The second highest ranked factor was the slowness of the client’s decision-making. Delay in settling contractor claims by clients and delay in design approvals were the third most significant factors within the group. During the covid pandemic, claims from the government to contractors were delayed, as priority was given to healthcare and not development. According to the responses, errors in design and specifications were the least significant factors in delaying a construction project. This can be partly attributable to a majority of poorly unqualified subcontractors.

Contractor-related factors

The calculated RII and the ranking for eight factors categorised under contractor-related factors are shown in Table 6.

Table 6. RII and ranking of contractor-related factors.
Delay factors RII Rank
Q9 Poor planning and scheduling. 0.7890 3
Q10 Shortage of skilled subcontractors/suppliers. 0.8294 1
Q11 Financial difficulties of contractors. 0.8233 2
Q12 Disagreements between the contractor and other parties. 0.6724 7
Q13 Poor site management, monitoring, and control. 0.7742 4
Q14 Errors during construction. 0.6454 8
Q15 Underestimating the project duration. 0.6945 6
Q16 Regular changes of the subcontractor’s staff. 0.6957 5

Source: Authors’ calculations.

According to the results, the shortage of skilled subcontractors/suppliers was the top ranked factor within the group. Financial difficulties of contractors were identified as the second most significant factor which affects the timely completion of a construction project. The inability of the client to fund the contractor properly, can trouble the contractors when carrying out the construction work. The third top ranked factor was poor planning and scheduling. The contractors should be able to prioritise the critical activities when planning the project at the initial stage. Ignoring such critical activities will lead to delays in the construction project. Errors during construction were identified as the least significant factor within the group.

Consultant-related factors

Table 7 shows the ranking and the calculated RII for the factors categorised under consultant-related factors. This group contained eight factors that delay a construction project.

Table 7. RII and ranking of consultant-related factors.
Delay factors RII Rank
Q17 Delay in inspections and completed work approvals. 0.6466 6
Q18 Delay in material and payment approval. 0.6994 1
Q19 Errors in contract documents. 0.6123 8
Q20 Constant design changes by the consultant 0.6736 4
Q21 Delay in preparing and approving drawings and design documents. 0.6896 2
Q22 Lack of experienced consultants. 0.6626 5
Q23 Errors in design documents. 0.6393 7
Q24 Poor coordination and communication. 0.6773 3

Source: Authors’ calculations.

Delay in material and payment approval was the most significant factor that could delay a construction project’s completion. The consultants should be able to reduce the amount of time they take for material and payment approvals, to avoid delays in construction work. The second highest priority factor for delay included preparing and approving drawings and design documents. Poor coordination and communication between consultants and other stakeholders were the third highest ranked delay factor. The group’s least important factor was errors in contract documents.

Resource-related factors

The calculated RII and the ranking of factors categorised under resource-related factors are shown in Table 8. Eight factors were included in this group.

Table 8. RII and ranking of resource-related factors.
Delay factors RII Rank
Q25 Shortage of labourers (Skilled, semi-skilled, unskilled) 0.8245 1
Q26 Delay in delivering materials to the site. 0.8098 2
Q27 Poor material handling at the site. 0.6859 7
Q28 Low productivity of labourers. 0.7485 5
Q29 Fluctuation of material prices in the market. 0.7890 3
Q30 Inadequate numbers of equipment. 0.7828 4
Q31 Failure of equipment. 0.7018 6
Q32 Personal disagreements between labourers. 0.5411 8

Source: Authors’ calculations.

The top ranking factor was the shortage of labourers (Skilled, semi-skilled, unskilled). As a result of the Covid-19 pandemic situation, employing labourers for construction projects has been difficult. Due to lockdowns and travel restrictions, labourers could not travel from their home areas to the construction sites; also, it is unfeasible to provide accommodation to a large number of labourers. Delay in delivering materials to the site was the second highest ranked delay factor within the group. The third most important factor was the fluctuation of material prices in the market, another result of the economic crisis due to Covid-19. Among the eight factors, personal disagreements between labourers were found to be the least important project delay factor.

External factors

Table 9 shows the ranking and the calculated RII for the external factors. This group contained seven different delay factors.

Table 9. RII and ranking of external factors.
Delay factors RII Rank
Q33 Delay in obtaining permissions/approvals from the government. 0.7558 2
Q34 Unknown subsurface conditions. (Soil condition, water table etc.) 0.6859 3
Q35 Bad weather conditions. 0.6528 4
Q36 Accidents during construction. 0.5043 7
Q37 Changes in laws and regulations from the government. 0.5313 6
Q38 Delay in utility services. (Electricity, water etc.) 0.6491 5
Q39 Covid-19 pandemic situation 0.7902 1

Source: Authors’ calculations.

According to the results, the current Covid-19 pandemic has adversely affected the construction industry. Hence, the results showed the Covid-19 pandemic situation as the top-ranked delay factor within the external factors group. Delay in obtaining approvals from the government was the second most important factor, while unknown subsurface conditions. (Soil condition, water table etc.) were identified as the third top-ranked delay factor. Accidents during construction were the least significant project delay factor.

Ranking based on a group of factors

It is a crucial step in this study to identify the most significant group of factors which could affect the timely completion of a construction project. Therefore, the RII for each group of factors was found by calculating the average RII of the factors within each group. Table 10 shows the calculated RII and the ranking for each group of factors.

Table 10. RII and ranking of group of factors.

Group of factors RII Rank
Client/Owner related factors 0.7017 3
Contractor related factors 0.7405 1
Consultant related factors 0.6626 4
Resource related factors 0.7354 2
External factors 0.6528 5

Source: Authors’ calculations.

According to Table 10, the highest ranked group of factors was the contractor-related factors group. The second most important group of factors was the resource-related factors group. The third and fourth-ranked groups were client/owner-related factors group and the consultant-related factors group, respectively. The group which contained the external factors had the least influence on the timely completion of construction projects. Fig 4 shows the graphical depiction of the RII for each group of factors.

Fig 4. Graphical depiction of RII for each group of factors.

Fig 4

Source: Authors’ illustration.

Qualitative database created from the open-ended question in the questionnaire

Of the 163 respondents, 38 answered the open-ended question where they could present their opinion on construction project delays. Fig 5 presents the word cloud, which was generated using this question.

Fig 5. Qualitative database.

Fig 5

Source: Generated by www.wordcloud.com.

According to Fig 5, most of the respondents used the word “contractor” when providing their answers. The importance of obtaining this result was that it depicted a direct relationship with the results obtained from the descriptive analysis of the study, where the most influential group of factors was the “contractor-related factors” group. Secondly, the term “inexperience” has been used to describe the lack of skilled labourers, contractors, subcontractors, and suppliers at a construction site. The respondents have widely used words such as “materials”, and “insufficient”. This can be reconfirmed according to the descriptive analysis, where the “resource-related factors” was the second-ranked group of factors. The respondents have also used the word " political ", where political influence when selecting contractors, political interference on construction work and the country’s political instability significantly influenced the delays in construction projects. Therefore, descriptive analysis results can be validated.

Conclusion

The present study explored factors which could affect the timely completion of construction projects in Sri Lanka. The diverse perspectives of clients, contractors and consultants were considered to analyse the most significant factors for delays.

The study’s main objective was to identify the most critical factors that could affect the timely completion of construction projects in Sri Lanka. Thirty nine factors were identified through a comprehensive literature review and expert opinion. These factors were categorised into five groups namely, client/owner related factors, contractor related factors, consultant related factors, resource related factors and external factors. A questionnaire was developed incorporating questions relevant to these factors, which was effective in collecting data from the selected 163 Civil Engineers in Sri Lanka. The collected data were analysed using the RII. The factors were ranked accordingly to achieve the main objective of the study. The top ten project delaying factors were identified as, “Shortage of skilled subcontractors/suppliers”, “Shortage of labourers (Skilled, semi-skilled, unskilled)”, “Financial difficulties of contractors”, “Delay of delivering materials to site”, “Covid-19 pandemic situation”, “Fluctuation of material prices in the market”, “Poor planning and scheduling”, “Inadequate numbers of equipment”, “Poor site management, monitoring, and control” and “Delay in obtaining permissions/approvals from government”. According to the clients/owners and consultants, “Financial difficulties of contractors” was the most influential factor which delays a construction project. The contractors claimed that the “Shortage of skilled subcontractors/suppliers” was the most significant project delaying factor. Also, the most important group of factors was identified as the contractor related factors group. This was further confirmed by the qualitative database obtained by the respondents’ opinions. The most influential factor under the client/owner related factors was identified as the “Financial difficulties of clients”. “Shortage of skilled subcontractors/suppliers” ranked at the top of contractor related factors. “Delay in material and payment approval” and “Shortage of labours (Skilled, semi-skilled, unskilled)” were the most significant factors under consultant related factors and resource related factors respectively. When it comes to the external factors, “Covid-19 pandemic situation” was identified as the top ranked project delaying factor. The study’s findings could be used by the stakeholders of a construction project to avoid unnecessary delays.

The novelty of the study is that the insights would contribute to the engineering environment and are highly relevant to policymakers to improve the timely completion of construction projects in Sri Lanka. According to the present study’s results, the lack of skilled subcontractors and suppliers and the lack of labourers are key issues to be addressed in timely completion of a construction project. Operating with inexperienced and unskilled subcontractors and suppliers may be challenging for the contractors to complete project tasks on time. Further, employing an adequate number of labourers is a must to avoid project delays. The contractors should be funded promptly by the owners so that the former can continue without interruptions to workflow, material shortages etc. As a result, the contractors could support the construction work as scheduled while considering the time and cost constraints. However, this could be much more difficult when the client/owner also faces financial difficulties. When the materials are not available at the construction site for critical activities, it will delay the construction work, whereas the labourers would idle with interruption to work. Therefore, facilitating the transportation of supplies to the construction site without any delays is mandatory. This calls for effective logistics and supplies management. The material and payment processing (for timely approval etc.) should be done efficiently by the consultants to avoid any delays in the construction work. The construction industry suffered a setback amid the initial outbreak of the Covid-19 pandemic situation due to lockdowns and work disruptions. Moreover, labourers were scarce (as due to lockdown conditions, they had to be employed in their home areas); practical difficulties were observed when providing accommodation for the labourers (due to fear of Covid-19 health risks, renting was refused instead). Currently, the market price of materials has fluctuated considerably and is rising. This is because the pandemic has extended to an economic crisis, imports were restricted, and then supplies became limited and expensive. Thus, planning too has become challenging, adversely affecting the cost aspects, exceeding pro forma budgets in every construction project, which has affected its timely completion. The contractors should be able to properly plan and schedule the site work at the initial stage. Apart from these, the site work should be properly managed, monitored, and controlled by the contractor at the initiation stage. Rationally, if contractors are skilled and of integrity, their selection is independent and transparent, then time overruns can be minimised to a certain extent. The required construction equipment should be available in adequate numbers at the construction site. Providing efficient services in granting permissions and approvals by the government authorities plays a major role in completing a construction project within the given time, as it postpones the start of the project.

Limitations

Even though the study contributes largely to the construction industry in Sri Lanka, there could be some limitations which can be addressed in future research. The sample size could be expanded to be representative, compared to the large population of Civil Engineers employed in different types of construction work in Sri Lanka. This approach can assist for wide coverage and a comprehensive study to gain useful findings to avoid construction delays and related losses.

Recommendations and policy implications

Based on the study’s results, the financial difficulties of both contractors and clients should be evaluated for the successful completion of construction projects. Also, experienced subcontractors, suppliers and labourers should be available to avoid project delays. A skilled workforce is a must but lacking in the Sri Lankan setting. A transparent approach and unbiased selection of suitable contractors are mandatory to minimise root causes.

The timely completion of any construction project has a significant effect on the success of the project. Currently, the Sri Lankan construction industry is undergoing a booming phase, meaning meeting high demand and avoiding interruptions are vital. Therefore, the construction projects must be delivered on time without any delays, as it can also affect the country’s overall economy. Therefore, the results of this study will be useful for the stakeholders to identify areas that deserve much focus and attention. Based on the findings of this research, the stakeholders can plan adequately, schedule, control and monitor the construction activities. Further, they can avoid losing revenue, undue delays, incurring additional costs and ensure credibility. The Sri Lankan government can use the findings of this study to foresee the reasons for delays in various construction projects and devise necessary mitigation measures.

Supporting information

S1 Appendix. Questionnaire.

(DOCX)

S2 Appendix. Data file.

(XLSX)

Acknowledgments

The authors would like to thank Ms. Gayendri Karunarathne for proof-reading and editing this manuscript.

Data Availability

All relevant data are within the manuscript and its Supporting Information files (S2 Appendix. Data File).

Funding Statement

The authors received no specific funding for this work.

References

  • 1.Central Bank of Sri Lanka. Annual Report 2020. Colombo: Centrl Bank of Sri Lanka, 2022. [Google Scholar]
  • 2.Construction Industry Development Authority. Development of Sri Lanka’s Construction Industry: The Way Forward After COVID 19. Colombo 7: 2020. [Google Scholar]
  • 3.Singh R. Delays and cost overruns in infrastructure projects: extent, causes and remedies. Economic and Political Weekly. 2010:43–54. [Google Scholar]
  • 4.Catalão FP, Cruz CO, Sarmento JM. The determinants of time overruns in Portuguese public projects. Journal of Infrastructure Systems. 2021;27(2):05021002. [Google Scholar]
  • 5.Santoso DS, Gallage PGMP. Critical factors affecting the performance of large construction projects in developing countries. Journal of Engineering, Design and Technology. 2019;18(3):531–56. doi: 10.1108/jedt-05-2019-0130 [DOI] [Google Scholar]
  • 6.Gardezi SSS, Manarvi IA, Gardezi SJS. Time Extension Factors in Construction Industry of Pakistan. Procedia Engineering. 2014;77:196–204. doi: 10.1016/j.proeng.2014.07.022 [DOI] [Google Scholar]
  • 7.Mpofu B, Ochieng EG, Moobela C, Pretorius A. Profiling causative factors leading to construction project delays in the United Arab Emirates. Engineering, Construction and Architectural Management. 2017;24(2):346–76. doi: 10.1108/ecam-05-2015-0072 [DOI] [Google Scholar]
  • 8.Durdyev S, Omarov M, Ismail S, Shukla SK. Causes of delay in residential construction projects in Cambodia. Cogent Engineering. 2017;4(1). doi: 10.1080/23311916.2017.1291117 [DOI] [Google Scholar]
  • 9.Aziz RF, Abdel-Hakam AA. Exploring delay causes of road construction projects in Egypt. Alexandria Engineering Journal. 2016;55(2):1515–39. doi: 10.1016/j.aej.2016.03.006 [DOI] [Google Scholar]
  • 10.Hoque MI, Safayet MA, Rana MJ, Bhuiyan AY, Quraishy GS. Analysis of construction delay for delivering quality project in Bangladesh. International Journal of Building Pathology and Adaptation. 2021;ahead-of-print(ahead-of-print). doi: 10.1108/ijbpa-03-2021-0032 [DOI] [Google Scholar]
  • 11.We Alaghbari, Razali A. Kadir M, Salim A, Ernawati. The significant factors causing delay of building construction projects in Malaysia. Engineering, Construction and Architectural Management. 2007;14(2):192–206. doi: 10.1108/09699980710731308 [DOI] [Google Scholar]
  • 12.Zailani S, Ariffin HAM, Iranmanesh M, Moeinzadeh S, Iranmanesh M. The moderating effect of project risk mitigation strategies on the relationship between delay factors and construction project performance. Journal of Science and Technology Policy Management. 2016;7(3):346–68. doi: 10.1108/jstpm-12-2015-0041 [DOI] [Google Scholar]
  • 13.Yap JBH, Goay PL, Woon YB, Skitmore M. Revisiting critical delay factors for construction: Analysing projects in Malaysia. Alexandria Engineering Journal. 2021;60(1):1717–29. doi: 10.1016/j.aej.2020.11.021 [DOI] [Google Scholar]
  • 14.Enshassi A, Al‐Najjar J, Kumaraswamy M. Delays and cost overruns in the construction projects in the Gaza Strip. Journal of Financial Management of Property and Construction. 2009;14(2):126–51. doi: 10.1108/13664380910977592 [DOI] [Google Scholar]
  • 15.Mahamid I. Risk matrix for factors affecting time delay in road construction projects: owners’ perspective. Engineering, Construction and Architectural Management. 2011;18(6):609–17. doi: 10.1108/09699981111180917 [DOI] [Google Scholar]
  • 16.Elawi GSA, Algahtany M, Kashiwagi D. Owners’ Perspective of Factors Contributing to Project Delay: Case Studies of Road and Bridge Projects in Saudi Arabia. Procedia Engineering. 2016;145:1402–9. doi: 10.1016/j.proeng.2016.04.176 [DOI] [Google Scholar]
  • 17.Alsuliman JA. Causes of delay in Saudi public construction projects. Alexandria Engineering Journal. 2019;58(2):801–8. doi: 10.1016/j.aej.2019.07.002 [DOI] [Google Scholar]
  • 18.Assaf S, Hassanain MA, Abdallah A, Sayed AMZ, Alshahrani A. Significant causes of claims and disputes in construction projects in Saudi Arabia. Built Environment Project and Asset Management. 2019;9(5):597–615. doi: 10.1108/bepam-09-2018-0113 [DOI] [Google Scholar]
  • 19.Al-Hazim N, Salem ZA, Ahmad H. Delay and Cost Overrun in Infrastructure Projects in Jordan. Procedia Engineering. 2017;182:18–24. doi: 10.1016/j.proeng.2017.03.105 [DOI] [Google Scholar]
  • 20.Ahmad HS, Ayoush MD, Al-Alwan MS. Causes of delay to public infrastructure projects according to engineers representing different contract parties. Built Environment Project and Asset Management. 2019;10(1):153–79. doi: 10.1108/bepam-03-2019-0026 [DOI] [Google Scholar]
  • 21.Parchami Jalal M, Shoar S. A hybrid SD-DEMATEL approach to develop a delay model for construction projects. Engineering, Construction and Architectural Management. 2017;24(4):629–51. doi: 10.1108/ecam-02-2016-0056 [DOI] [Google Scholar]
  • 22.Shahsavand P, Marefat A, Parchamijalal M. Causes of delays in construction industry and comparative delay analysis techniques with SCL protocol. Engineering, Construction and Architectural Management. 2018;25(4):497–533. doi: 10.1108/ecam-10-2016-0220 [DOI] [Google Scholar]
  • 23.Jahangoshai Rezaee M, Yousefi S, Chakrabortty RK. Analysing causal relationships between delay factors in construction projects. International Journal of Managing Projects in Business. 2019;14(2):412–44. doi: 10.1108/ijmpb-01-2019-0020 [DOI] [Google Scholar]
  • 24.Wang T-K, Ford DN, Chong H-Y, Zhang W. Causes of delays in the construction phase of Chinese building projects. Engineering, Construction and Architectural Management. 2018;25(11):1534–51. doi: 10.1108/ecam-10-2016-0227 [DOI] [Google Scholar]
  • 25.Prasad KV, Vasugi V, Venkatesan R, Bhat N. Analysis of causes of delay in Indian construction projects and mitigation measures. Journal of Financial Management of Property and Construction. 2019;24(1):58–78. doi: 10.1108/jfmpc-04-2018-0020 [DOI] [Google Scholar]
  • 26.Marzouk MM, El-Rasas TI. Analyzing delay causes in Egyptian construction projects. Journal of Advanced Research. 2014;5(1):49–55. Epub 2015/02/17. doi: 10.1016/j.jare.2012.11.005 ; PubMed Central PMCID: PMC4294731. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.El-Rasas T, Marzouk M. Fuzzy model for assessing delays in Egyptian residential projects. Journal of Financial Management of Property and Construction. 2020;25(2):225–46. doi: 10.1108/jfmpc-04-2019-0031 [DOI] [Google Scholar]
  • 28.Elhusseiny HO, Nosair I, Ezeldin AS. Systematic processing framework for analyzing the factors of construction projects’ delays in Egypt. Ain Shams Engineering Journal. 2021;12(2):1501–11. doi: 10.1016/j.asej.2020.10.016 [DOI] [Google Scholar]
  • 29.Amoatey CT, Rolf AL, Kjell Tryggestad P, Ameyaw YA, Adaku E, Famiyeh S. Analysing delay causes and effects in Ghanaian state housing construction projects. International Journal of Managing Projects in Business. 2015;8(1):198–214. doi: 10.1108/ijmpb-04-2014-0035 [DOI] [Google Scholar]
  • 30.Famiyeh S, Amoatey CT, Adaku E, Agbenohevi CS. Major causes of construction time and cost overruns. Journal of Engineering, Design and Technology. 2017;15(2):181–98. doi: 10.1108/jedt-11-2015-0075 [DOI] [Google Scholar]
  • 31.Mukuka M, Aigbavboa C, Thwala W. Effects of Construction Projects Schedule Overruns: A Case of the Gauteng Province, South Africa. Procedia Manufacturing. 2015;3:1690–5. doi: 10.1016/j.promfg.2015.07.989 [DOI] [Google Scholar]
  • 32.Gebrehiwet T, Luo H. Analysis of Delay Impact on Construction Project Based on RII and Correlation Coefficient: Empirical Study. Procedia Engineering. 2017;196:366–74. doi: 10.1016/j.proeng.2017.07.212 [DOI] [Google Scholar]
  • 33.Abebe M, Germew S, Laili Y. Investigation of significant industrial project delay factors and development of conceptual framework. Cogent Engineering. 2021;8(1). doi: 10.1080/23311916.2021.1938936 [DOI] [Google Scholar]
  • 34.Egwim CN, Alaka H, Toriola-Coker LO, Balogun H, Ajayi S, Oseghale R. Extraction of underlying factors causing construction projects delay in Nigeria. Journal of Engineering, Design and Technology. 2021;ahead-of-print(ahead-of-print). doi: 10.1108/jedt-04-2021-0211 [DOI] [Google Scholar]
  • 35.Fashina AA, Omar MA, Sheikh AA, Fakunle FF. Exploring the significant factors that influence delays in construction projects in Hargeisa. Heliyon. 2021;7(4):e06826. Epub 2021/05/14. doi: 10.1016/j.heliyon.2021.e06826 ; PubMed Central PMCID: PMC8085700. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Mwamvani HDJ, Amoah C, Ayesu-Koranteng E. Causes of road projects’ delays: a case of Blantyre, Malawi. Built Environment Project and Asset Management. 2021;ahead-of-print(ahead-of-print). doi: 10.1108/bepam-09-2021-0113 [DOI] [Google Scholar]
  • 37.Agyekum-Mensah G, Knight AD. The professionals’ perspective on the causes of project delay in the construction industry. Engineering, Construction and Architectural Management. 2017;24(5):828–41. doi: 10.1108/ecam-03-2016-0085 [DOI] [Google Scholar]
  • 38.Zidane YJT, Andersen B. The top 10 universal delay factors in construction projects. International Journal of Managing Projects in Business. 2018;11(3):650–72. doi: 10.1108/ijmpb-05-2017-0052 [DOI] [Google Scholar]
  • 39.Arantes A, Ferreira LMDF. Underlying causes and mitigation measures of delays in construction projects. Journal of Financial Management of Property and Construction. 2020;25(2):165–81. doi: 10.1108/jfmpc-03-2019-0029 [DOI] [Google Scholar]
  • 40.Lindhard SM, Neve H, Terje Kalsaas B, Møller DE, Wandahl S. Ranking and comparing key factors causing time-overruns in on-site construction. International Journal of Construction Management. 2020:1–7. doi: 10.1080/15623599.2020.1820659 [DOI] [Google Scholar]
  • 41.Kometa ST, Olomolaiye PO, Harris FC. Attributes of UK construction clients influencing project consultants’ performance. Journal of Construction Management and Economics. 1994;12(5):433–43. [Google Scholar]
  • 42.Cronbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika. 1951;16:297–334. [Google Scholar]
  • 43.Gliem JA, Gliem RR. Calculating, interpreting, and reporting Cronbach’s alpha reliability coefficient for likert type scales. Proceedings for MMidwest Research to Practice Conference in Adult, Continuing, and Community Education. 2003. [Google Scholar]

Decision Letter 0

Anu Sayal

2 Sep 2022

PONE-D-22-23136Why projects delay?: A study of timely completion of construction projects in Sri LankaPLOS ONE

Dear Dr. Ruwan Jayathilaka,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Oct 17 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

  • A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

  • A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

  • An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Dr. Anu Sayal, Ph.D.

Academic Editor

PLOS ONE

Journal requirements:

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1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at 

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: No

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #2: No

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This paper has attempted to: A study of timely completion of construction projects in Sri Lanka

The following items are helpful comments for the authors to consider:

• Please rewrite the title by using professional way.

• Please rewrite the abstract by using professional way.

• Use more technical keywords.

• The literature review is very shallow with no in-depth review for the previous related work and is not clear; I believe this could be significantly modified to give the important information.

• Problem description is not clear; I believe this should be significantly written in a more professional way.

Writing style of the manuscript is needed to be improved.

• Check the wiring sequence in the manuscript and improve it.

• Focus on your novelty and contribution to your paper especially at the conclusion.

• Discuss the formulas in more detail.

• Use the illustrative flowchart for methodology and sequence.

• More focus on questionnaire is needed.

• Please add all formulas with more details at your manuscript.

• Conclusion should be written in a more professional way.

• Please put list of abbreviations and symbols at the end of the manuscript.

• Some editorial and typo errors.

• There are some grammatical errors that need to be fixed.

• Please add and increase updated References with formatted outline.

Reviewer #2: The manuscript has been poorly written, while there many flaws. First of all, I have never seen any article which has an introduction section (problem statement) but without any references cited. This should mean that the entire section has been written based on your own findings.

Literature search has many missing articles on the subject and I don't understand the rationale behind the separation of the studies according to different countries, as this study is not a review study.

Literature review section is too long but not comprehensive.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PLoS One. 2022 Dec 15;17(12):e0278318. doi: 10.1371/journal.pone.0278318.r003

Author response to Decision Letter 0


28 Sep 2022

Point by point response to editor and reviewers

Dear editor and the reviewers,

We would like to express our profound appreciation to the editor and the reviewers for the valuable comments and suggestions made on our manuscript which were very helpful in revising and improving it.

Please note that the line numbers referred in this document is aligned with the revised manuscript which has track changes.

Reviewer 1 comment 1: Please rewrite the title by using professional way.

Authors’ Response to Reviewer 1 Comment 1: Comment has been well noted and the title is rewritten using professional way. This has included from line 1 to 2 and 26 to 27 as follows,

“A study on timely completion of construction projects in Sri Lanka”

Reviewer 1 comment 2: Please rewrite the abstract by using professional way.

Authors’ Response to Reviewer 1 Comment 2: Comment has been noted and the abstract is rewritten using professional way. This has included from line 29 to 47 as follows,

“Timely completion is a crucial factor for the success of a construction project, especially in the Sri Lankan context. This study aims to identify the most influential factors that affect the timely completion of construction projects in Sri Lanka. Thirty-nine factors were identified through a comprehensive literature review and experts’ opinions. A questionnaire was distributed incorporating the 39 project delay factors, and responses from 163 Civil Engineers were obtained. The Relative Importance Index (RII) analysed and ranked the project delay factors. The top ranked significant project delay factors were identified as shortage of skilled subcontractors/suppliers, shortage of labourers (Skilled, semi-skilled, unskilled), financial difficulties of contractors, delay in delivering materials to the site, and Covid-19 pandemic situation. According to the main three respondent types, i.e., clients/owners, contractors and consultants, the contractor related factors was the key group among others that delay a construction project. The scientific value of the study includes assisting the Sri Lankan construction industry to identify the factors affecting the timely completion of construction projects, and developing mitigation methods and strategies. Also, the stakeholders could duly schedule the construction work by identifying areas that need more attention. The contribution of this study would assist stakeholders to adopt a proactive approach by identifying mistakes on their part and minimising potential issues that lead to construction project delays in Sri Lanka.”

Reviewer 1 comment 3: Use more technical keywords.

Authors’ Response to Reviewer 1 Comment 3: Comment has been noted and it has been corrected in the revised manuscript from line number 49 to 50.

Reviewer 1 comment 4: The literature review is very shallow with no in-depth review for the previous related work and is not clear; I believe this could be significantly modified to give the important information.

Authors’ Response to Reviewer 1 Comment 4: Comment has been well noted and the literature review was modified by providing more information. This has corrected from line 130 to 297.

Reviewer 1 comment 5: Problem description is not clear; I believe this should be significantly written in a more professional way. Writing style of the manuscript is needed to be improved.

Authors’ Response to Reviewer 1 Comment 5: Comment has been well noted. The problem statement is included in the revised manuscript from line 67 to line 93.

Reviewer 1 comment 6: Check the wiring sequence in the manuscript and improve it.

Authors’ Response to Reviewer 1 Comment 6: Comment has been well noted. The writing of the manuscript is improved using professional way. The manuscript was also proofread and edited by a proof-reader.

Reviewer 1 comment 7: Focus on your novelty and contribution to your paper especially at the conclusion.

Authors’ Response to Reviewer 1 Comment 7: Thank you. The comment has been noted. The novelty and contribution of the study is included from line 581 to line 605 as follows,

“The novelty of the study is that the insights would contribute to the engineering environment and are highly relevant to policymakers to improve the timely completion of construction projects in Sri Lanka. According to the present study’s results, the lack of skilled subcontractors and suppliers and the lack of labourers are key issues to be addressed in timely completion of a construction project. Operating with inexperienced and unskilled subcontractors and suppliers may be challenging for the contractors to complete project tasks on time. Further, employing an adequate number of labourers is a must to avoid project delays. The contractors should be funded promptly by the owners so that the former can continue without interruptions to workflow, material shortages etc. As a result, the contractors could support the construction work as scheduled while considering the time and cost constraints. However, this could be much more difficult when the client/owner also faces financial difficulties. When the materials are not available at the construction site for critical activities, it will delay the construction work, whereas the labourers would idle with interruption to work. Therefore, facilitating the transportation of supplies to the construction site without any delays is mandatory. This calls for effective logistics and supplies management. The material and payment processing (for timely approval etc.) should be done efficiently by the consultants to avoid any delays in the construction work. The construction industry suffered a setback amid the initial outbreak of the covid-19 pandemic situation due to lockdowns and work disruptions. Moreover, labourers were scarce (as due to lockdown conditions, they had to be employed in their home areas); practical difficulties were observed when providing accommodation for the labourers (due to fear of Covid-19 health risks, renting was refused instead).”

Reviewer 1 comment 8: Discuss the formulas in more detail.

Authors’ Response to Reviewer 1 Comment 8: Comment has been well noted. The formula which was used in the study was strengthen by adding following paragraph. Please see lines from 356 to line 362.

“Weights were assigned to each factor by each respondent (1= Very low significance, 2= Low significance, 3= Average significance, 4= High significance, 5= Very high significance) were multiplied by the frequency of responses given to each factor, and the total sum of those two values was calculated. The result was divided by the multiplication of the highest weight (5) and the total count of respondents. The ranking of the delay factors was done using the RII. Overall rankings were calculated by combining the responses given by all the respondents.”

Reviewer 1 comment 9: Use the illustrative flowchart for methodology and sequence.

Authors’ Response to Reviewer 1 Comment 9: Comment has been noted and Figure 2 was added to the revised manuscript to show flowchart for methodology and research sequence. This is sated in line number 306 to 307.

Reviewer 1 comment 10: More focus on questionnaire is needed.

Authors’ Response to Reviewer 1 Comment 10: Comment has been well noted. Detail discussion of the questionnaire has been added to the revised manuscript. This has included from line 318 to line 330.

Reviewer 1 comment 11: Please add all formulas with more details at your manuscript.

Authors’ Response to Reviewer 1 Comment 11: Comment has been well noted. The one formula which was used in the study was discussed in more detail from line 347 to line 362.

Reviewer 1 comment 12: Conclusion should be written in a more professional way.

Authors’ Response to Reviewer 1 Comment 12: Comment has been noted and the conclusion is rewritten in a more professional way. This has included from line 570 to 526.

Reviewer 1 comment 13: Please put list of abbreviations and symbols at the end of the manuscript.

Authors’ Response to Reviewer 1 Comment 13: Thank you for the comment. As per the PLOS ONE journal guideline abbreviation should define upon the first appearance in the text. Not as the list of abbreviation. Please check the following link for more details.

https://journals.plos.org/plosone/s/submission-guidelines#loc-abbreviations

Authors would like to keep the abbreviation as per the PLOS ONE guidelines.

Reviewer 1 comment 14: Some editorial and typo errors.

Authors’ Response to Reviewer 1 Comment 14: Comment has been noted. The editorial and typo errors were corrected in the revised manuscripts.

Reviewer 1 comment 15: There are some grammatical errors that need to be fixed.

Authors’ Response to Reviewer 1 Comment 15: The revised manuscript was also proofread once the changes were done and therefore, now, we can confirm that the revised manuscript is free of punctuation and grammatical errors.

Reviewer 1 comment 16: Please add and increase updated References with formatted outline.

Authors’ Response to Reviewer 1 Comment 16: Comment has been well noted and the references has been updated in revised manuscript.

Reviewer 2 comment 1: The manuscript has been poorly written, while there many flaws. First of all, I have never seen any article which has an introduction section (problem statement) but without any references cited. This should mean that the entire section has been written based on your own findings.

Authors’ Response to Reviewer 2 Comment 1: Thank you. Comment has been well noted. The citations were updated in the introduction section, and the problem statement is also included in the revised manuscript from line 67 to line 93.

Reviewer 2 comment 2: Literature search has many missing articles on the subject and I don't understand the rationale behind the separation of the studies according to different countries, as this study is not a review study.

Authors’ Response to Reviewer 2 Comment 2: Comment has been noted. The reason for separating the studies based on the continents was included from line 133 to line 138.

Reviewer 2 comment 3: Literature review section is too long but not comprehensive.

Authors’ Response to Reviewer 2 Comment 3: Thank you. Comment has been well noted and the literature review was modified by providing important information in the revised manuscript from line number 130 to 297.

Attachment

Submitted filename: Response to Reviewers.docx

Decision Letter 1

Anu Sayal

21 Oct 2022

PONE-D-22-23136R1A study on timely completion of construction projects in Sri LankaPLOS ONE

Dear Dr. Ruwan Jayathilaka,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by November 5, 2022. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

  • A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

  • A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

  • An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Dr. Anu Sayal, Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: (No Response)

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #3: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #3: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #3: Please support the efforts already put in this work by making further revision on the areas highighted in the review report

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Attachment

Submitted filename: REVIEW REPORT.docx

PLoS One. 2022 Dec 15;17(12):e0278318. doi: 10.1371/journal.pone.0278318.r005

Author response to Decision Letter 1


29 Oct 2022

Point by point response to editor and reviewers

Dear editor and the reviewers,

We would like to express our profound appreciation to the editor and the reviewers for the valuable comments and suggestions made on our manuscript which were very helpful in revising and improving it.

Please note that the line numbers referred in this document is aligned with the revised manuscript which has track changes.

Reviewer’s Comment 1: Suggested improvement in Title: Factors influencing the timely completion of construction projects in Sri Lanka

Authors’ Response to Comment 1: Thank you. Comment has been well noted and the suggested title has been used for as the new title of the revised manuscript from line 2 to 3 and 28 to 29.

“Factors influencing the timely completion of construction projects in Sri Lanka”

Reviewer’s Comment 2: Sampling technique used was not captured in the abstract.

Authors’ Response to Comment 2: Comment has been well noted. The sampling technique which was used in the has been included in the revised manuscript line number 36 to 37.

“A questionnaire incorporating the 39 project delay factors was distributed among 163 Civil Engineers, and responses were obtained. Random sampling method was adopted to select the sample.”

Reviewer’s Comment 3: Improve the keywords, see suggestions; Construction projects, Time overrun, Relative Importance Index (RII), Delay factors,

Sri Lanka

Authors’ Response to Comment 3: Comment has been well noted. The suggested keywords have been added to the revised manuscript line number from 51 to 52.

“Keywords: Construction projects, Time Overrun, Relative Importance Index (RII), Delay factors, Sri Lanka”

Reviewer’s Comment 4: There are a lot of grammar errors and poor sentence construction. Avoid short sentences that do not make a complete sense.

Authors’ Response to Comment 4: Comment has been well noted. Grammar errors and poor sentence construction have been resolved in the revised manuscript.

Reviewer’s Comment 5: The introduction section says a lot about your work. You have to strengthen the research problem and gap. Consult more literature, there a lot of them on time performances factors in construction. Just 7 citations in this very important subject are not enough. Remove less important sentences; be concise in your approach.

Authors’ Response to Comment 5: Comment has been well noted. More literature have been added in the revised manuscript from line 68 to 84.

“The nature of the construction industry can be considered as uncertain. Construction projects differ from each other depending on the project size, project objectives, project duration, etc. Every project is unique on its own and no project has the same characteristics. Even though the construction projects nowadays use advanced and new project management theories and technologies, the delay in the completion of projects cannot be mitigated [3].

The time deviation of a construction project can be defined as the difference between specified project duration and the real project duration. There can be three types of time deviations in a construction project. Firstly, is a negative deviation, where the real duration is less than the specified duration. Secondly, there is the no particular deviation type, where the specified duration and the real duration are the same. Thirdly, is the positive deviation, where the real duration is greater than the specified duration. This positive deviation is also known as the time overrun, where the delays in the project completions occur. When the delay period is long, consequently the effects will also be greater/significant, which can exert a negative impact on the project. For the successful completion of a project, cost, quality as well as time, should be properly utilised [4].”

Reviewer’s Comment 6: The review section is satisfactory. However, some grammar editing is required.

Authors’ Response to Comment 6: Comment has been well noted. Grammar editing has been done for the revised manuscript.

Reviewer’s Comment 7: Why only civil engineers: Justify please. Could you not have obtained robust data if other experts in the construction industry were included?

Authors’ Response to Comment 7: Comment has been well noted. The reason for obtaining data from Civil Engineer has been included in the revised manuscript line number from 323 to 325.

“….Qualified Civil Engineers were selected as the population, since they are engaged in the construction work under all three stakeholder groups namely, client/owner, consultant and contractor…..”

Reviewer’s Comment 8: Sampling method adopted in the electronic administration of questionnaire was not stated.

Authors’ Response to Comment 8: Comment has been well noted. The sampling method is included in line 328 in the revised manuscript.

“…Then, the final questionnaire was distributed to 1,416 respondents selected using a random sampling method from 2,716 Civil Engineers included in the list…..”

Reviewer’s Comment 9: Justify the choice of questionnaire. Why was questionnaire used in this study?

Authors’ Response to Comment 9: Comment has been well noted. The reason for selecting questionnaire method has been include from line 302 to 304 in the revised manuscript.

“As the research strategy, survey strategy was adopted for the study where a questionnaire was developed in which the project delay factors were included. The respondents were able to rank each factor according to their significance, with the use of a questionnaire….”

Reviewer’s Comment 10: There was the lack of a clear explanation/description of the position of the outcome of this study with existing knowledge in the same subject area. Relate your results/finding to existing reports on the subject area. Please discussion your findings. How does it relate to the review you did?

Authors’ Response to Comment 10: Comment has been well noted. This has been included in the revised manuscript from line 389 to 400.

“…This result alligned with the results obtained by Yap, Goay (11) and Wang, Ford (22). Shortage of labourers (Skilled, semi-skilled, unskilled) was the second most significant factor (RII=0.8245) categorised under resource-related factors. This result can be further confirmed by the results obtained by Durdyev, Omarov (6) who conducted a study in Cambodia to identify the time overrun factors in residential building construction projects in the country. These factors seem realistic in the construction industry as most subcontracts/suppliers and labourers are not skilled. The third highest ranked factor was the financial difficulties of contractors (RII=0.8233), another contractor-related factor. In Malaysia, two research studies (9), (11) confirmed that the financial difficulties of the contractor play a major role in delaying construction projects, while Prasad, Vasugi (23) have also received the same result in the research they conducted in India…..”

Reviewer’s Comment 11: Please review this section to showcase and improve on the efforts put in previous sections. Especially regarding key factors and relationships. Avoid unnecessary ingredients in the conclusion section.

Authors’ Response to Comment 11: Comment has been well noted. This has been included in the revised manuscript from line 561 to 584.

“…..These factors were categorised into five groups namely, client/owner related factors, contractor related factors, consultant related factors, resource related factors and external factors. A questionnaire was developed incorporating questions relevant to these factors, which was effective in collecting data from the selected 163 Civil Engineers in Sri Lanka. The collected data were analysed using the RII. The factors were ranked accordingly to achieve the main objective of the study. The top ten project delaying factors were identified as, “Shortage of skilled subcontractors/suppliers”, “Shortage of labourers (Skilled, semi-skilled, unskilled)”, “Financial difficulties of contractors”, “Delay of delivering materials to site”, “Covid-19 pandemic situation”, “Fluctuation of material prices in the market”, “Poor planning and scheduling”, “Inadequate numbers of equipment”, “Poor site management, monitoring, and control” and “Delay in obtaining permissions/approvals from government”. According to the clients/owners and consultants, “Financial difficulties of contractors” was the most influential factor which delays a construction project. The contractors claimed that the “Shortage of skilled subcontractors/suppliers” was the most significant project delaying factor. Also, the most important group of factors was identified as the contractor related factors group. This was further confirmed by the qualitative database obtained by the respondents’ opinions. The most influential factor under the client/owner related factors was identified as the “Financial difficulties of clients”. “Shortage of skilled subcontractors/suppliers” ranked at the top of contractor related factors. “Delay in material and payment approval” and “Shortage of labours (Skilled, semi-skilled, unskilled)” were the most significant factors under consultant related factors and resource related factors respectively. When it comes to the external factors, “Covid-19 pandemic situation” was identified as the top ranked project delaying factor…..”

Reviewer’s Comment 12: Does this study have limitations? What recommendation do you have for future studies?

Authors’ Response to Comment 12: Comment has been well noted. Limitations of the study has been included in the revised manuscript from line 620 to 626. Recommendations has been included from line 628 to 643.

“Even though the study contributes largely to the construction industry in Sri Lanka, there could be some limitations which can be addressed in future research. The sample size could be expanded to be representative, compared to the large population of Civil Engineers employed in different types of construction work in Sri Lanka. This approach can assist for wide coverage and a comprehensive study to gain useful findings to avoid construction delays and related losses.”

“Based on the study's results, the financial difficulties of both contractors and clients should be evaluated for the successful completion of construction projects. Also, experienced subcontractors, suppliers and labourers should be available to avoid project delays. A skilled workforce is a must but lacking in the Sri Lankan setting. A transparent approach and unbiased selection of suitable contractors are mandatory to minimise root causes.

The timely completion of any construction project has a significant effect on the success of the project. Currently, the Sri Lankan construction industry is undergoing a booming phase, meaning meeting high demand and avoiding interruptions are vital. Therefore, the construction projects must be delivered on time without any delays, as it can also affect the country's overall economy. Therefore, the results of this study will be useful for the stakeholders to identify areas that deserve much focus and attention. Based on the findings of this research, the stakeholders can plan adequately, schedule, control and monitor the construction activities. Further, they can avoid losing revenue, undue delays, incurring additional costs and ensure credibility. The Sri Lankan government can use the findings of this study to foresee the reasons for delays in various construction projects and devise necessary mitigation measures.”

Reviewer’s Comment 13: Does this study have implications?

Authors’ Response to Comment 13: Comment has been well noted. Policy implications have been added in the revised manuscript from line 629 to 643.

“Based on the study's results, the financial difficulties of both contractors and clients should be evaluated for the successful completion of construction projects. Also, experienced subcontractors, suppliers and labourers should be available to avoid project delays. A skilled workforce is a must but lacking in the Sri Lankan setting. A transparent approach and unbiased selection of suitable contractors are mandatory to minimise root causes.

The timely completion of any construction project has a significant effect on the success of the project. Currently, the Sri Lankan construction industry is undergoing a booming phase, meaning meeting high demand and avoiding interruptions are vital. Therefore, the construction projects must be delivered on time without any delays, as it can also affect the country's overall economy. Therefore, the results of this study will be useful for the stakeholders to identify areas that deserve much focus and attention. Based on the findings of this research, the stakeholders can plan adequately, schedule, control and monitor the construction activities. Further, they can avoid losing revenue, undue delays, incurring additional costs and ensure credibility. The Sri Lankan government can use the findings of this study to foresee the reasons for delays in various construction projects and devise necessary mitigation measures.”

Reviewer’s Comment 14: Revisit the reference list and make sure it conforms to the journals’ guide/format

Authors’ Response to Comment 14: Comment has been well noted. Reference list has been created as per the PLOS ONE journal guidelines. Please check the following link for more details. https://journals.plos.org/plosone/s/submission-guidelines/#loc-reference-style

Attachment

Submitted filename: Response to Reviewers.docx

Decision Letter 2

Anu Sayal

4 Nov 2022

PONE-D-22-23136R2Factors influencing the timely completion of construction projects in Sri LankaPLOS ONE

Dear Dr. Jayathilaka,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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We look forward to receiving your revised manuscript.

Kind regards,

Anu Sayal, Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments:

Suggested improvement in Title: Factors influencing the timely completion of construction projects in Sri Lanka

ABSTRACT

  1. Sampling technique used was not captured in the abstract.

KEYWORDS-improve the keywords, see suggestions

  1. Construction projects, Time overrun, Relative Importance Index (RII), Delay factors,

    Sri Lanka

INTRODUCTION SECTION

  1. There a lot of grammar errors and poor sentence construction. Avoid short sentences that do not make a complete sense. There a lot of these type of sentences, for example,

  2. The introduction section says a lot about your work. You have to strengthen the research problem and gap. Consult more literature, there a lot of them on time performances factors in construction. Just 7 citations in this very important subject are not enough. Remove less important sentences; be concise in your approach.

LITERATURE REVIEW SECTION

  1.  The review section is satisfactory, however, some grammar editing is required

METHODOLOGY SECTION

Overall, the methodology adopted is satisfactory, bit it can be made better by attending to the followings;

  1. Why only civil engineers: Justify please. Could you not have obtained robust data if other experts in the construction industry were included?

  2. Sampling method adopted in the electronic administration of questionnaire was not stated.

  3. Justify the choice of questionnaire. Why was questionnaire used in this study?

DATA ANALYSIS SECTION

  1. There was the lack of a clear explanation/description of the position of the outcome of this study with existing knowledge in the same subject area. Relate your results/finding to existing reports on the subject area. Please discussion your findings. How does it relate to the review you did?

CONCLUSIONS AND RECOMMENDATIONS

  1. Please review this section to showcase and improve on the efforts put in previous sections. Especially regarding key factors and relationships. Avoid unnecessary ingredients in the conclusion section.

  2. Does this study have limitations? What recommendation do you have for future studies?

  3. Does this study have implications?

REFERENCES

Revisit the reference list and make sure it conforms to the journals’ guide/format

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

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PLoS One. 2022 Dec 15;17(12):e0278318. doi: 10.1371/journal.pone.0278318.r007

Author response to Decision Letter 2


5 Nov 2022

Point by point response to editor and reviewers

Dear editor and the reviewers,

We would like to express our profound appreciation to the editor and the reviewers for the valuable comments and suggestions made on our manuscript which were very helpful in revising and improving it.

Please note that the line numbers referred in this document is aligned with the revised manuscript which has track changes.

Comments of Editor

Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Authors’ Response to Editor: Thank you very much and comment has been well noted. Reference list has been created as per the PLOS ONE journal guidelines. PLOS ONE uses “Vancouver” style and authors also double check the referencing style with the recently published articles in PLOS ONE. Authors would like to confirm reference list is complete and correct. As per the reviewer 1 feedback below, following two references have been added to the introduction section of the revised manuscript to strengthen the research problem and gap of the study.

3. Singh R. Delays and cost overruns in infrastructure projects: extent, causes and remedies. Economic and Political Weekly. 2010:43-54.

4. Catalão FP, Cruz CO, Sarmento JM. The determinants of time overruns in Portuguese public projects. Journal of Infrastructure Systems. 2021;27(2):05021002.

In our previous manuscript there were 41 references and it has increased to 43 with the current revised manuscript. Since this study is related to the Sri Lanka authors would like to keep the Sri Lankan literature.

Addition Editor Comments:

Reviewer’s Comment 1: Suggested improvement in Title: Factors influencing the timely completion of construction projects in Sri Lanka

Authors’ Response to Comment 1: Thank you. Comment has been well noted and the suggested title has been used for as the new title of the revised manuscript from line 2 to 3 and 28 to 29.

“Factors influencing the timely completion of construction projects in Sri Lanka”

Reviewer’s Comment 2: Sampling technique used was not captured in the abstract.

Authors’ Response to Comment 2: Comment has been well noted. The sampling technique which was used in the has been included in the revised manuscript line number 36 to 37.

“A questionnaire incorporating the 39 project delay factors was distributed among 163 Civil Engineers, and responses were obtained. Random sampling method was adopted to select the sample.”

Reviewer’s Comment 3: Improve the keywords, see suggestions; Construction projects, Time overrun, Relative Importance Index (RII), Delay factors,

Sri Lanka

Authors’ Response to Comment 3: Comment has been well noted. The suggested keywords have been added to the revised manuscript line number from 51 to 52.

“Keywords: Construction projects, Time Overrun, Relative Importance Index (RII), Delay factors, Sri Lanka”

Reviewer’s Comment 4: There are a lot of grammar errors and poor sentence construction. Avoid short sentences that do not make a complete sense.

Authors’ Response to Comment 4: Comment has been well noted. Grammar errors and poor sentence construction have been resolved in the revised manuscript.

Reviewer’s Comment 5: The introduction section says a lot about your work. You have to strengthen the research problem and gap. Consult more literature, there a lot of them on time performances factors in construction. Just 7 citations in this very important subject are not enough. Remove less important sentences; be concise in your approach.

Authors’ Response to Comment 5: Comment has been well noted. More literature have been added in the revised manuscript from line 68 to 84. The following references have been added to revised manuscript to strengthen the research problem and the research gap.

3. Singh R. Delays and cost overruns in infrastructure projects: extent, causes and remedies. Economic and Political Weekly. 2010:43-54.

4. Catalão FP, Cruz CO, Sarmento JM. The determinants of time overruns in Portuguese public projects. Journal of Infrastructure Systems. 2021;27(2):05021002.

“The nature of the construction industry can be considered as uncertain. Construction projects differ from each other depending on the project size, project objectives, project duration, etc. Every project is unique on its own and no project has the same characteristics. Even though the construction projects nowadays use advanced and new project management theories and technologies, the delay in the completion of projects cannot be mitigated [3].

The time deviation of a construction project can be defined as the difference between specified project duration and the real project duration. There can be three types of time deviations in a construction project. Firstly, is a negative deviation, where the real duration is less than the specified duration. Secondly, there is the no particular deviation type, where the specified duration and the real duration are the same. Thirdly, is the positive deviation, where the real duration is greater than the specified duration. This positive deviation is also known as the time overrun, where the delays in the project completions occur. When the delay period is long, consequently the effects will also be greater/significant, which can exert a negative impact on the project. For the successful completion of a project, cost, quality as well as time, should be properly utilised [4].”

Reviewer’s Comment 6: The review section is satisfactory. However, some grammar editing is required.

Authors’ Response to Comment 6: Comment has been well noted. Grammar editing has been done for the revised manuscript.

Reviewer’s Comment 7: Why only civil engineers: Justify please. Could you not have obtained robust data if other experts in the construction industry were included?

Authors’ Response to Comment 7: Comment has been well noted. The reason for obtaining data from Civil Engineer has been included in the revised manuscript line number from 323 to 325.

“….Qualified Civil Engineers were selected as the population, since they are engaged in the construction work under all three stakeholder groups namely, client/owner, consultant and contractor…..”

Reviewer’s Comment 8: Sampling method adopted in the electronic administration of questionnaire was not stated.

Authors’ Response to Comment 8: Comment has been well noted. The sampling method is included in line 328 in the revised manuscript.

“…Then, the final questionnaire was distributed to 1,416 respondents selected using a random sampling method from 2,716 Civil Engineers included in the list…..”

Reviewer’s Comment 9: Justify the choice of questionnaire. Why was questionnaire used in this study?

Authors’ Response to Comment 9: Comment has been well noted. The reason for selecting questionnaire method has been include from line 302 to 304 in the revised manuscript.

“As the research strategy, survey strategy was adopted for the study where a questionnaire was developed in which the project delay factors were included. The respondents were able to rank each factor according to their significance, with the use of a questionnaire….”

Reviewer’s Comment 10: There was the lack of a clear explanation/description of the position of the outcome of this study with existing knowledge in the same subject area. Relate your results/finding to existing reports on the subject area. Please discussion your findings. How does it relate to the review you did?

Authors’ Response to Comment 10: Comment has been well noted. This has been included in the revised manuscript from line 389 to 400.

“…This result alligned with the results obtained by Yap, Goay (11) and Wang, Ford (22). Shortage of labourers (Skilled, semi-skilled, unskilled) was the second most significant factor (RII=0.8245) categorised under resource-related factors. This result can be further confirmed by the results obtained by Durdyev, Omarov (6) who conducted a study in Cambodia to identify the time overrun factors in residential building construction projects in the country. These factors seem realistic in the construction industry as most subcontracts/suppliers and labourers are not skilled. The third highest ranked factor was the financial difficulties of contractors (RII=0.8233), another contractor-related factor. In Malaysia, two research studies (9), (11) confirmed that the financial difficulties of the contractor play a major role in delaying construction projects, while Prasad, Vasugi (23) have also received the same result in the research they conducted in India…..”

Reviewer’s Comment 11: Please review this section to showcase and improve on the efforts put in previous sections. Especially regarding key factors and relationships. Avoid unnecessary ingredients in the conclusion section.

Authors’ Response to Comment 11: Comment has been well noted. This has been included in the revised manuscript from line 561 to 584.

“…..These factors were categorised into five groups namely, client/owner related factors, contractor related factors, consultant related factors, resource related factors and external factors. A questionnaire was developed incorporating questions relevant to these factors, which was effective in collecting data from the selected 163 Civil Engineers in Sri Lanka. The collected data were analysed using the RII. The factors were ranked accordingly to achieve the main objective of the study. The top ten project delaying factors were identified as, “Shortage of skilled subcontractors/suppliers”, “Shortage of labourers (Skilled, semi-skilled, unskilled)”, “Financial difficulties of contractors”, “Delay of delivering materials to site”, “Covid-19 pandemic situation”, “Fluctuation of material prices in the market”, “Poor planning and scheduling”, “Inadequate numbers of equipment”, “Poor site management, monitoring, and control” and “Delay in obtaining permissions/approvals from government”. According to the clients/owners and consultants, “Financial difficulties of contractors” was the most influential factor which delays a construction project. The contractors claimed that the “Shortage of skilled subcontractors/suppliers” was the most significant project delaying factor. Also, the most important group of factors was identified as the contractor related factors group. This was further confirmed by the qualitative database obtained by the respondents’ opinions. The most influential factor under the client/owner related factors was identified as the “Financial difficulties of clients”. “Shortage of skilled subcontractors/suppliers” ranked at the top of contractor related factors. “Delay in material and payment approval” and “Shortage of labours (Skilled, semi-skilled, unskilled)” were the most significant factors under consultant related factors and resource related factors respectively. When it comes to the external factors, “Covid-19 pandemic situation” was identified as the top ranked project delaying factor…..”

Reviewer’s Comment 12: Does this study have limitations? What recommendation do you have for future studies?

Authors’ Response to Comment 12: Comment has been well noted. Limitations of the study has been included in the revised manuscript from line 620 to 626. Recommendations has been included from line 628 to 643.

“Even though the study contributes largely to the construction industry in Sri Lanka, there could be some limitations which can be addressed in future research. The sample size could be expanded to be representative, compared to the large population of Civil Engineers employed in different types of construction work in Sri Lanka. This approach can assist for wide coverage and a comprehensive study to gain useful findings to avoid construction delays and related losses.”

“Based on the study's results, the financial difficulties of both contractors and clients should be evaluated for the successful completion of construction projects. Also, experienced subcontractors, suppliers and labourers should be available to avoid project delays. A skilled workforce is a must but lacking in the Sri Lankan setting. A transparent approach and unbiased selection of suitable contractors are mandatory to minimise root causes.

The timely completion of any construction project has a significant effect on the success of the project. Currently, the Sri Lankan construction industry is undergoing a booming phase, meaning meeting high demand and avoiding interruptions are vital. Therefore, the construction projects must be delivered on time without any delays, as it can also affect the country's overall economy. Therefore, the results of this study will be useful for the stakeholders to identify areas that deserve much focus and attention. Based on the findings of this research, the stakeholders can plan adequately, schedule, control and monitor the construction activities. Further, they can avoid losing revenue, undue delays, incurring additional costs and ensure credibility. The Sri Lankan government can use the findings of this study to foresee the reasons for delays in various construction projects and devise necessary mitigation measures.”

Reviewer’s Comment 13: Does this study have implications?

Authors’ Response to Comment 13: Comment has been well noted. Policy implications have been added in the revised manuscript from line 629 to 643.

“Based on the study's results, the financial difficulties of both contractors and clients should be evaluated for the successful completion of construction projects. Also, experienced subcontractors, suppliers and labourers should be available to avoid project delays. A skilled workforce is a must but lacking in the Sri Lankan setting. A transparent approach and unbiased selection of suitable contractors are mandatory to minimise root causes.

The timely completion of any construction project has a significant effect on the success of the project. Currently, the Sri Lankan construction industry is undergoing a booming phase, meaning meeting high demand and avoiding interruptions are vital. Therefore, the construction projects must be delivered on time without any delays, as it can also affect the country's overall economy. Therefore, the results of this study will be useful for the stakeholders to identify areas that deserve much focus and attention. Based on the findings of this research, the stakeholders can plan adequately, schedule, control and monitor the construction activities. Further, they can avoid losing revenue, undue delays, incurring additional costs and ensure credibility. The Sri Lankan government can use the findings of this study to foresee the reasons for delays in various construction projects and devise necessary mitigation measures.”

Reviewer’s Comment 14: Revisit the reference list and make sure it conforms to the journals’ guide/format

Authors’ Response to Comment 14: Comment has been well noted. Reference list has been created as per the PLOS ONE journal guidelines. Please check the following link for more details. https://journals.plos.org/plosone/s/submission-guidelines/#loc-reference-style

Attachment

Submitted filename: Response to Reviewers.docx

Decision Letter 3

Anu Sayal

15 Nov 2022

Factors influencing the timely completion of construction projects in Sri Lanka

PONE-D-22-23136R3

Dear Dr. Ruwan Jayathilaka,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Dr. Anu Sayal, Ph.D.

Academic Editor

PLOS ONE

Acceptance letter

Anu Sayal

16 Nov 2022

PONE-D-22-23136R3

Factors influencing the timely completion of construction projects in Sri Lanka

Dear Dr. Jayathilaka:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

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Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Anu Sayal

Academic Editor

PLOS ONE

Associated Data

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    Supplementary Materials

    S1 Appendix. Questionnaire.

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    Data Availability Statement

    All relevant data are within the manuscript and its Supporting Information files (S2 Appendix. Data File).


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