Table 3. Themes identified through framework analysis of semi-structured interviews. Illustrative quotes related to each theme are provided, with examples from individuals in differing roles, where relevant. More extensive illustrative examples related to each theme are available in supplementary materials.

Individual Level	Illustrative quote 1	Illustrative quote 2
Provision and quality of training for the research team (IND1)	We had some training from [IVCC member of staff 1] on the development of SOPs... I also had training on GLP which was conducted in Moshi. That was the first one. It was big because it combined different sites… It exposed us to this process, why do we need to do it, why should we change our attitudes towards what we are doing, what's the value of it. Laboratory Supervisor	We initially conducted external training for all staff on general GLP principles from [IVCC member of staff 2] which was useful as it put all evels of staff on a strong foundation. Test Facility Manager
Recognition of research leadership/ esteem (IND2)	I think the team as well would be happy to see the products which have been evaluated here and found to be effective as seen in the market… I’m saying this because I’ve been involved in evaluating a number of these products. When I go out there even in other missions and I found those products in the market, it's a great feeling and I can tell the story. GLP Project Coordinator	Yes, because we are now professional. Professional in everything-- when you do something and you see the results you think, "Yes, I've done it." It's a feeling of professionalism. Technician
Career trajectory (IND3)	I must admit that in the government system, we don't train these people that much. Here, the system was good for scientists and technicians but not for supportive staff. With GLP, at least they're now considered. They get training on what to do, which is very good for their career as well. Research Scientist	Yes, for instance, it's good in your resume if you're working in a place which has accreditation, it’s a big plus. It means you're fit to work there. Technician
Structured work practices (IND4)	Because of how GLP wants you to work, it helps you to be creative. To be creative, so that you can do what you are supposed to do. That has helped me a lot. To manage the work, and to manage the people you're working with. Laboratory Supervisor	I think I actually learned a better way of how to maintain or how to keep track of what I'm doing. This has actually been a good way from you actually know like everything where everything is and if I want to remember something, I don't have to actually guess about it. I have a log of everything that I have done. Administrator
Transfer of organisation skills to home (IND5)	When we talk about GLP, the best thing it gave us is a way to govern your life. Because apart from being here working with GLP, it helps also us to know that in life you have to follow some guideline, and you have to do things followed by some rules. Personally, I have found this very instructive. GLP Manager	GLP also is teaching us how to be punctual. Not punctual only in the working place, but in your family. GLP is helping us to save, in saving, in budgeting. That is something which somebody can't see, so is to me is indirect benefit. Laboratory Supervisor
Institutional level
Career pathways for the research team (INS1)	There is what we call performance appraisal. Normally we appraise people quarterly. I do find things they are moving more easily, because people have to fill the forms. When you see the comments from the head of department, you find heads of department are doing their part. Even the staff are doing their part. I find it has made my work easy. Administrator	People, I think, generally want to be trained more. Maybe that desire always existed but there wasn't a channel for people to voice that and now there is. We have appraisals, we have the training committee. Study Director
Sustainable provision of appropriate, high quality training (INS2)	Internally, there have been trainings on GLP several times. Those trainings concerned general aspects of GLP and specific aspects such as writing SOPs and their use. Those internal trainings were done at our institution by the quality manager and the supervisors. Laboratory Supervisor	Also, it advertises the college as well. We have been training some the college students at the Master's level, and they've been attached here for their Master's as well. GLP Project Coordinator
Nationally/ internationally competitive research and grants (INS3)	That is one of the success that we had. Also, the other issue is that we managed to attract some clients, looking for our technical support and the evaluation of their products. For instance, for the phase one evaluation of products-- Since the inception of the workshop in Liverpool, we had about three-phase one studies. Test Facility Manager	We can give data that is trustworthy since it is collected in a defined standard and by using well maintained and validated equipment. Most of all, the output of good quality data from research is for the benefit of the whole community i.e. when we say a certain product is efficacious then it’s really so. This then means protection of the whole public. Quality Assurance Manager
Research environment – infrastructure (INS4a)	I think that before when you worked in different projects the infrastructure was sometimes not adapted to the entomology. Now the infrastructure is there, when you go to the insectarium and to the lab you see there is new materials. There are meeting rooms, and the archive office. Also, in [Field Site] there is a new building. We see that there is some evolution. Laboratory Supervisor	You can see now the condition of working for every one of us-- scientists, the technicians, the assistants-- has been very drastically improved. Even there at the [Field Site], the rooms now, they are very comfortable for the people who are sleeping; very comfortable. Laboratory Supervisor
Research environment (b) – IT, human resources, procurement (INS4b)	I'll actually say the computers are not really that expensive, but the major part is having the main primary place where you can actually do everything. For us, it made it easier for us to control most of our research activities. We have created easier, formal ways to access things. I think with the findings and everything that we've got it, it should help a lot with putting up research. Data Manager	Each service had its way of doing their work. With the SOPs, they guide them to do the things they need to do for each task. For instance, we had processes in accounts, but they have a lot of papers, documents that they have to validate, if it is to procure some material, some things, it will come to their site, they would just validate it. But with the SOP, you know what to validate, what you shouldn't validate. So, it's kind of a guiding that help them, each service interacts more smoothly. Administrator
Structured working practices (INS5)	First, we have learned to be accountable. I myself I have learned to value every [national currency] that we get; to get value for money. The way we used to work before GLP is quite different. GLP money has done more than what we expected it could do, after starting, working with the seriousness, making sure that we get standard material, things like that. Laboratory Supervisor	It helped the management and technical team to focus efforts in a more structured way for general working practices and enabled full traceability of test items and experiments. Test Facility Manager
National/ International level
National: research councils/research productivity (NAT1)	For example, we have a centre for medical entomology and veterinary they really want us to train their students to use our lab and there is the National Institute for Public hygiene they're doing a lot of entomology survey and they want us to process the sample. I told you about the PMI project, so we're using the lab to process the mosquito sample we collect. Director	You can see that GLP becomes very interesting. It becomes a centre of excellence for training in this area. These government universities prefer to go to a government institution or centre. Laboratory Supervisor
International: networks/ collaborations (NAT2)	We visited [Collaborating Test Facility] to see how they have- how they have gone, how far have they gone, and what challenges they did. We learned from them, actually. Laboratory Supervisor	As a network with other institutions, like we have local institution like [Collaborating Test Facility] who have already been accredited, and because we have collaboration with [Vector Control Network], we are working with them. We have the network from West Africa and also there are other people from [UK Institution] actually because our long collaborators. We get a lot of technical support from different people in terms of advice and what to do. And because of their advice we can make sure the site is well equipped and meets the requirements for GLP. Test Facility Manager
Research impact and user engagement (NAT3)	As [Test Facility], I think the main benefit is to provide - we normally say that if you don’t have data, you don’t have the right to speak - to provide data which will actually influence the policy change for vector control in the country. GLP Project Coordinator	The Ministry of Health are anxious because the [Umbrella Institution] is the technical arm of the Ministry of Health, so they are looking forward to make sure they have a very competent technical arm that can provide good advice related to vector control and evaluation of new vector control tools. Test Facility Manger
Effect of investment in surrounding community (NAT4)	Those people, they really liked the project. The same people from the environment were very happy to be involved in part of the work. They said, “It's useful for us. Our kids stay there. They live there.” It was easy to recruit people for working there in the site. Very easy. Laboratory Supervisor	The renovation activity which has been done here benefitted the entire community of [Region]. The businesspeople who we are working with, the retailer shops where we were getting materials for the construction, the people here who worked here, we all benefited from this. That money went to them, actually, we had to buy materials and to construct. We had good relationship with them during the entire process. Even there at the villages, the way we renovated our buildings, the way we are taking care of the road to reach there… because of the projects that keeps the volunteers, they get some incentives, things like that, it has been very nice. They got the benefit out of it. GLP Project Coordinator