Engineered systems today must be protected from a variety of hazards including engineering failures, terrorism effects, and natural disasters. With the development of increasingly complicated engineered systems has come a rise in the difficultly of determining all possible failure modes of these systems. Therefore, it is desirable to design and develop systems that not only have well-defined failure modes but also can withstand or endure some unanticipated failures without catastrophic loss of life or property. To aid engineers in approaching this challenge, the concept of a “resilient” system has been developed.

The concept of system resilience has been developed by taking inspiration from material resilience from the materials science field. A definition has been proposed that defines system resilience as the amount of energy a system can absorb before that system reaches its yield stress. System properties such as input energy, input exergy, and exergy destroyed, have been used to develop specific variables for characterizing system resilience. System characterization curves (similar to material stress-strain curves) have been developed to aid in visualizing the concept of resilience for a variety of different systems and system changes. These curves also help with identifying specific yield stress points for each system.

This paper will present the background information which inspired this research, show the process used to develop both the system resilience definition and the specific variables used to characterize system resilience, as well as show examples of system characterization curves for specific process systems including a steam pipe and a water pump. Additionally, future opportunities, directions, and questions for this research will be explored.