Decision Analysis for Optimal Design Concept: Hybridized Fuzzified Weighted Decision Matrix and Fuzzy TOPSIS Using Design for X Tools

Abstract

The need for designs with extended capabilities and customization calls for a robust conceptual design phase of an equipment or a product. It becomes important to appraise different design concepts using a holistic approach for the comparison process in order to obtain an optimal design. In this article, a decision analysis for selecting optimal design of a Reconfigurable Assembly Fixture (RAF) from a set of alternative design concepts is presented by developing a Multi-Attribute Decision Model (MADM). The MADM developed in this article hybridize the aggregating strength of the fuzzified weighted decision matrix and computational strength of the fuzzy TOPSIS in terms of separation from positive and negative solutions and closeness coefficient to ideal solution. The design for X tools (manufacture, assembly and disassembly, maintenance, reliability, life cycle cost, serviceability and environment) are used to represent the design features and factors or constraints for evaluating the designs with several sub-factors in order to have a robust decision process. Two other tools added to the X-tools are design for reconfigurability and functionality. These two tools were added in order to consider the reconfigurable characteristic features for the design concepts of the RAFs. Results obtained from the decision process proves that there are slight differences in the final values of the design concepts which can be linked to the performance of each design concept in the decision process and the weights or priority of the design features. Also, the close variations in the final values of the design concepts may be due to inclusion of weights of the design attributes in computation of the distances to the positive and negative ideal solutions.