Selecting alternatives in the conceptual design phase: an application of Fuzzy-AHP and Pugh’s Controlled Convergence

Abstract

The selection of conceptual design alternatives is crucial in product development. This is due both to the fact that an iterative process is required to solve the problem and that communication among design team members should be optimized. In addition, several design constraints need to be respected. Although the literature offers several alternative selection methods, to date, only very few are currently being used in industry. A comparison of the various approaches would improve the knowledge transfer between design research and practice, helping practitioners to approach these decision support tools more effectively. This paper proposes a structured comparison of two decision support methods, namely the Fuzzy-Analytic Hierarchy Process and Pugh’s Controlled Convergence. From the literature debate regarding selection methods, four relevant criteria are identified: computational effort, suitability for the early design stages, suitability for group decision making, and ease of application. Finally a sensitivity analysis is proposed to test the robustness of each method. An industrial case study is described regarding an innovative and low-cost solution to increase the duration of heel tips in women’s shoes. The selection of conceptual design alternatives of the heel tip presents complex challenges because of the extremely difficult geometric constraints and demanding design criteria

Redesign of an In-Market Conveyor System for Manufacturing Cost Reduction and Design Efficiency Using DFMA Methodology

“…He developed a method of controlled convergence which is an iterative and non-numeric tool that improves and narrows the choice of concepts available. 'Controlled convergence', developed by Stuart Pugh in the 1980s, utilises a convenient matrix to compare concepts with a selection of predetermined requirements [19]. The decision matrix is built based on Pugh's technique to evaluate and rate the ideas.…”

Developing Design Methods - a Conceptual Requirement Framework

“…1.1. Ease of Use addresses frequent complaints of practitioners that methods are too complex (Becerril et al, 2017) or difficult to apply (Renzi et al, 2015). Ease of Use is a measurement of how easy it is for the user to apply the method and comprises two Level 3 requirement subcategories: "ease of interaction" and "autonomy of method use".…”

Pugh matrix and aggregated by extent analysis using trapezoidal fuzzy number for assessing conceptual designs

“…1). In actual fact, having an allencompassing design that satisfies all design requirements or features is a goal that seems not achievable because of the dynamic nature of the market that is swamped with diverse design due to customers' requirements (Olabanji & Mpofu, 2014;Renzi et al, 2015;Toh & Miller, 2015). Given this, the design process usually involves the development of different design concepts based on functional requirements and design features.…”

“…Hereafter, the decision-making team will collect the design concepts in order to select the optimal design concept (Okudan & Shirwaiker, 2006;Akay et al, 2011;Aikhuele, 2017). Decision making in the conceptual phase of engineering design usually involves an evaluation of the design alternatives based on the identified and grouped design features and subfeatures respectively (Green & Mamtani, 2004;Renzi et al, 2015). Two tasks that are usually done by design experts and decision-makers are assigning weights to the relative importance of the design features in the optimal design and assigning weights to the sub-features in order to ascertain and quantify their contributions to the performance of the design features (Girod et al, 2003;Arjun Raj & Vinodh, 2016;Chakraborty et al, 2017).…”