Abstract
Process systems are negatively impacted by manufacturing uncertainties, and increasingly by unknown-unknown disruptive events. To this effect, systems need to be designed with the inherent flexibility and resilience to overcome the impacts of uncertainties and disruptions respectively as it is more challenging to retrofit existing systems with such capabilities. To this end, we propose a methodology based on flexibility analysis to systematically explore the feasibility of design alternatives under parameter uncertainty and discrete disruption scenarios simultaneously. Multi-parametric programming is utilized to generate explicit relationships between design decisions and the resulting system’s ability to maintain feasible operations under uncertainty and disruptive events. We capture this ability by introducing the Combined Flexibility-Resilience Index (CFRI), which describes the likelihood that the system is feasible under the relevant uncertainty and disruption sets. With explicit functions for the CFRI, the flexibility and resilience objectives can be incorporated into a general superstructure design optimization problem alongside other objectives, allowing for the exploration of trade-offs among flexibility, cost and resilience. Our methodology provides the foundation of a holistic approach for design optimization for both flexibility and resilience. A case study involving a process plant with multiple sources of uncertainties and disruptive events is used to illustrate the application of the proposed methodology.