Satisficing2 (squared) in system of systems engineering design

Abstract

Recent applications of methodologies that include principles of bounded rationality have resulted in techniques such as satisficing strategies to assist with decision making in multi-objective, interdependent, and complex systems and system of systems. These strategies are most appropriate for design and decision-making situations where the modeling, simulation, and testing can be lengthy and thus optimization or experimenting on a large number of candidate solutions is infeasible. As a result, a satisficing approach, where, once a solution is found that meets the requirements, objectives, or aspiration levels of the stakeholder(s), is implemented to make the decision or select the design alternative. At least two potential issues can occur with this particular strategy: 1) if the first design tested surpasses the aspiration levels successfully for all objectives, the decision maker may be hesitant to accept this solution, unsure of the ease at which future designs might also exceed aspiration levels, and 2) if no designs tested reach the aspiration levels of all objectives, even after the time or expense allotted for testing is complete, a decision maker faces the dilemma of whether or not their aspiration levels are impossible to reach under any design parameters or conditions. If one is unduly worried about the first of these two problems and responds by adjusting the aspirations levels higher accordingly, this can increase the probability of the second problem. This paper proposes a strategy of applying a second layer of the principles of satisficing to the classical satisficing strategy, collectively called the “satisficing squared” S2 method. The S2 method will be explored in selecting a portfolio of technologies to assist reaching the goals of NASA's Environmentally Responsible Aviation Project.