Since parts and systems are closely linked to each other in complex engineering products, a change in a single part or system causes changes in other parts or systems, which in turn propagate through a product. This paper proposes an analytic network process (ANP) approach to measuring the relative importance of parts and modules in a modular product in terms of design change impacts and propagation. Although the primary purpose of the ANP is selection and prioritisation of alternatives, this study applies the ANP to change propagation by exploiting its advantageous feature, taking indirect impacts among elements into account. To begin with, a design dependency network that represents design change relationships among parts and modules is constructed as a network model of the ANP. The ANP procedure is then carried out to derive the relative change impacts (RCIs) of parts and modules. The RCI values can be used for various works in engineering change management. A case study on an automobile system is presented to illustrate the proposed approach.

In order to improve ease of disassembly and recycling of a product at its retirement stage, it is essential to design a product architecture that allows for easy disassembly and recycling. In this paper, a novel concept of eco-architecture is introduced, and the eco-architecture analysis, a design approach supporting the end-of-life decision making process, is proposed. The eco-architecture is the product architecture described from the end-of-life (EOL) viewpoint, in which a product is represented as an assembly of end-of-life modules. Not only does it prescribe an EOL strategy, but it also gives information about the connections and arrangement among EOL modules. Therefore, understanding the eco-architecture is helpful in enhancing the disassembly and recycling capabilities of an architecture design. The proposed eco-architecture analysis supports architecture improvement; it helps designers to derive the most desirable eco-architecture which entails the optimal end-of-life strategy. It also facilitates the extraction of meaningful redesign guidelines which make it possible to improve an architecture in an efficient and effective manner.