A Sensitivity-based Approach for Identification of Flexible Design Opportunities in Engineering System Design

Engineering system can provide value over time in a dynamic environment when system's components are designed with flexibility. This paper presents a sensitivity-based method to identify where to add flexibility within systems when considering external uncertainty. The sensitivity-based method defines the sensitivity of design variables which are measured by the number of exogenous factors that can directly or indirectly influence them. The relationships of design variables and exogenous factors are represented by directed graph in this paper. In addition, a DFS-based algorithm is proposed to quantitatively and efficiently measure the sensitivity of each design variable when inter-relationship within a system is complex. A case study on the design of a High Speed Rail (HSR) system is used to demonstrate the proposed approach. Results show that the proposed approach can quantitatively identify all the flexible design opportunities. Furthermore, adding flexibility into the selected opportunity will result in significant reduction in the total project's over long term.