A Comparison of Concept Selection in Concept Scoring and Axiomatic Design Methods

Abstract

The appropriate selection of design concepts has a strong influence on product cost, durability, robustness and functionality. Effective tools to identify good design concepts are critical. Different design methodologies have different objectives to aid in making the right decision. Some design methods are complementary, whereas others may provide contradictory results. In this study, two design methods, concept scoring and axiomatic design, are compared for their ability to obtain good design concepts. Conceptual designs of micro-pumps, which provide pressure gradients to actuate the flow of liquids and gas, are used to evaluate the design methods. Metrics are used to compare these two design methodologies’ abilities to achieve objective evaluations. The concept scoring method is easy to use, especially when comparing different designs. The axiomatic design method provides a structured and mathematical design evaluation; however, achieving good design through the uncoupling or decoupling of matrices is challenging. Further study is required to integrate these two design methods.

Application of Axiomatic Design principles in conceptual design

“…Application of AD principles to concept evaluation relies more on technical knowledge, compared to other methods used for evaluation, since the designer reformulates the needs perceived by the customer into the functional requirements [12]. Therefore, this results in an evaluation process based on the fulfilment and independence of functional requirements and may reduce biased personal judgments [7]. However, Axiomatic Design doesn't provide a way to check whether the CNs have been adequately reformulated to FRs.…”

“…Secondly, there is a lack of guidelines for incorporating different types of requirements and criteria in concept evaluation. For instance, non-technical requirements are defined as constraints and, as such, are not part of the design matrix (and, consequently, not part of the evaluation) [7]. This exclusion of non-technical requirements can result in unaesthetic and costly products that fail to satisfy customer needs [11].…”

“…One of the main advantages of Axiomatic Design, in terms of concept evaluation, is the timely detection of internal technical conflicts in generated concepts through the Independence Axiom [7]. Other advantages include the ability to evaluate complete and incomplete information criteria together [8] and visualise dependencies between design parameters [9].…”

“…However, evaluation is often applied at the end of the conceptual design phase to concepts that were not solely generated using AD principles. Defining the best concept among them is time-consuming compared to other concept evaluation methods, such as concept scoring and Pugh's method [7]. This is due to the process of finding an independent set of functional requirements (FRs) and design parameters (DPs), which is iterative especially for complex designs.…”

Numerical Study of a Left Ventricular Assist Device (LVAD) With Different Blade Heights and Tip Clearances

“…There are several ways of obtaining an optimized model configuration out of almost infinite variations such as using Taguchi Method [24], Response Surface Method [25,26], ranked selection method [27,28]. In this study, screening and scoring method is used.…”