Modelling and optimisation of upgradability in the design of multiple life cycle products: a critical review

Design for Upgradability (DfU) is one of remanufacturing strategies that extend the product lifetime through the functional enrichment of the product. Multiple Life Cycle products (MLPs) are designed with ease-of-upgrade features to allow for product upgrading to be made once the product is not functioning or becomes obsolete. To date, researches on product upgradability have generally focussed on the design features and the attributes of upgradability. However, there have been limited studies on how DfU can be applied concurrently in the product design process with the integration of modelling and optimisation process. This paper is aimed at providing insights on the significance of DfU in product sustainability. A detailed account on the works of earlier researchers that have contributed to the body of knowledge on design upgradability is also presented and discussed. A review on the modelling and optimisation methods commonly deployed in the search for corresponding design alternatives is presented and critically discussed in view of their applicability as tools to choose the best upgradable product design. The paper concludes with suggestions for further research focussing on the tools to enhance design upgradability and their significance in the development of products for multiple life cycles.