Toward an Early-Phase Conceptual System Design Risk-Informed Decision Making Framework

Current methods of risk analysis conducted during the early phases of complex system design do not give a clear voice to the customer or design engineer when considering engineering risk attitude in the dynamic shaping of early-phase conceptual design trade study outcomes. The existing methods either collect risk information following the completion of a conceptual design thus treating risk as an afterthought during trade studies, make risk-informed decisions prior to the conduction of trade studies thus artificially constraining the design space, or do not consider risk at all. This paper proposes a risk-informed decision making framework that offers a new, meaningful way of accounting for risk during trade studies, informs design decisions during trade studies with pertinent risk information, and takes into account risk attitude of the design engineer or customer when risk-informed decisions are made. Risk is elevated to the same level of importance as other system level variables in trade studies and risk-based decisions are made by individual subsystem engineers through the lens of risk appetite. Several previously developed methods of risk trading, assessing engineering risk attitude, and making risk-informed decisions based upon engineering risk attitude using utility theory are synthesized into the risk-informed decision-making framework. Implementation methods for trade studies being performed by groups of people and automatically by computers are presented. Sensitivity of the framework to input variable variation is examined. A spacecraft example is employed to demonstrate the usefulness of the framework. This paper provides a novel framework for risk-informed design decisions made within trade studies that are based upon engineering risk attitudes in early phase conceptual design.