Table 5.

Research gaps and research agenda regarding obsolescence and product design.

Aspect	Research gap	Research agenda
Design approaches for addressing obsolescence	i) Research on defining requirements in the product design process has been limited. More research is necessary to identify product design attributes that impact product obsolescence. ii) There is not a formal identification of product design attributes related to the different types of obsolescence such as technological, functional, psychological economic, DMSMS, and Planned. iii) Little attention has been paid to defining materials as a design strategy. More research is needed to understand the appearance and wear of materials during their life cycle.	i) Developing additional approaches focused on determining the definition of requirements and design attributes that impact product obsolescence (promoting or delaying) ii) Generating formal design rules aimed at delaying obsolescence and slowing the loop of resources iii) Characterizing product attributes or features respect to the different types of obsolescence iv) Developing approaches aimed at defining/selecting materials to achieve product durability from the early design stages considering the product life cycle.
Metrics for measuring product obsolescence	iv) Obsolescence forecasting metrics have focused on defining whether the scenario happens but do not consider what type of obsolescence the product may exhibit. Consequently, it can be challenging to determine the most effective design strategy to reduce obsolescence. v) Most of the research focuses on metrics for electronic products.	v) Developing additional obsolescence assessment tools focused on types of obsolescence. vi) Developing more design methods and indicators to measure, determine and predict product obsolescence in different lifecycle scenarios.
Obsolescence in product families	vi) There is a lack of research oriented to product families and product platforms, particularly when it comes to analyzing different types of obsolescence	vii) Conducting research on obsolescence concerning product families and product platforms, which are commonly employed to develop products across multiple generations and promote the sharing of design tasks, manufacturing processes, and modules