Identifying Redesign Pathways Over a Planned Number of Modifications to Support Change Management

Abstract Complex engineered systems evolve with the world around them as operating environments change and new demands arise. Yet, modifying these systems remains a challenge. Changes can easily propagate, making it difficult to limit the scope of system modifications. Mitigating, or preventing, change propagation enables more efficient redesign. In this paper, we develop a method for identifying feasible system configurations that are accessible within a discrete number of modifications. With this information, designers can consider modifications where change propagation is controlled. We leverage Complete Flexibility Ranges (CFRs), the extent to which a decision variable (DV) can change while maintaining system feasibility, to identify feasible changes. By modifying DVs in their CFRs, designers guarantee change will not propagate further. We also demonstrate how feasible configurations can be produced from strings of modifications, given that the final modification involves a DV changing within its CFR. The proposed method is applied to a high-powered rocket system to identify new configurations that could be created given different modification strings. The results from our study support the belief that modifying sets of DVs can be more efficient than modifying DVs independently and consecutively. We also show that making infeasible changes may enable greater exploration of the design space but may limit further change options. The proposed method could be applied in future work to 1) compare the performance of different redesign strategies, 2) explore the impact of decision selection order, and 3) develop heuristics for design for changeability. This work provides a foundation for further study on how to efficiently design and redesign changeable systems.