Managing assumption-driven design change via margin allocation and trade-offs

El Fassi, S., Chen, X., Riaz, A., Guenov, M. D., van Heerden, A. S.J. and Jimeno Altelarrea, S. (2023) Managing assumption-driven design change via margin allocation and trade-offs. Journal of Engineering Design, (doi: 10.1080/09544828.2023.2259741) (Early Online Publication)

Abstract

Assumptions are commonly introduced to fill gaps in knowledge during the engineering design process. However, the uncertainty inherent in these assumptions constitutes a risk that ought to be mitigated. That is, assumptions can negatively impact the system if they turn out to be invalid. Adverse effects may include system failure, violation of requirements, or budget and schedule overruns. In this paper, the relationships between assumptions and margins are made explicit, with the purpose of aiding risk mitigation, as well as accommodating future opportunities such as product evolvability. To this end, a novel assumption management framework is proposed, which consists of a taxonomy of margins, an algorithm for change absorber localisation, and an interactive approach for margin trade-off. The proposed framework is demonstrated with a conceptual aircraft design use case, which shows that the most relevant margins can be identified, given a revision of a set of assumptions. It is also demonstrated that the application of the method allowed the margins to be adjusted according to the confidence in the assumptions, while maintaining satisfaction of all design constraints, without unacceptable compromise of system performance.

• Item Type: Articles
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: van Heerden, Dr Stevan
• Authors: El Fassi, S., Chen, X., Riaz, A., Guenov, M. D., van Heerden, A. S.J., and Jimeno Altelarrea, S.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Journal of Engineering Design
• Publisher: Taylor and Francis
• ISSN: 0954-4828
• ISSN (Online): 1466-1837
• Published Online: 11 October 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Journal of Engineering Design 2023
• Publisher Policy: Reproduced under a Creative Commons License