Optimal Design of Modular Configuration Considering a Product Hierarchical Function Structure for Design for Environment

Abstract

Due to rise of environmental awareness in recent years, engineering designers are required to consider not only product model but also whole product lifecycle in order to reduce environmental burdens of their products. Modular design is originally a technique intended to shorten development period by parallel design for each module, improve productivity and reduce cost by standardization of modules. In recent years, modular design is also receiving attention in the research field of design for environment (DfE) and modular design for DfE has been studied for many researchers. This is because adequate modularization can improve product's recyclability, reusability, maintainability etc., which lead to improvement of product's environmental characteristics. This paper focuses on a modular design for DfE and proposes a new optimal design method that obtains the optimal modular configuration and the optimal lifecycle scenario of each module considering hierarchy of a product function structure. The proposed method configures modules based on a product function structure and validates configured modules by using DSM to guarantee functional feasibility of the modular configuration. Using such representation, modular design becomes a hierarchical problem, so, hierarchical genetic algorithm (HGA) is used to optimize the problem. In addition, to simultaneously optimize a modular configuration and a lifecycle scenario of each module, the proposed method enables lifecycle scenario to be designed for each module. In particular, reuse/recycle scenarios at end of life (EoL) stage are evaluated and the scenario with a higher score is selected for each module. Fitness of a design proposal of a modular configuration is based on their scores. In the case study, the proposed method is applied to the modular design of an inkjet printer.