USE OF A TROPHIC STRUCTURE TEST BED TO VALIDATE A NEW SYSTEMS-OF-SYSTEMS RESILIENCE METRIC

摘要

Systems of Systems (SoS) combine complex systems such as financial, transportation, energy, and healthcare systems to provide greater functionality. A failure in a constituent system, however, can render the entire SoS ineffective by causing cascading faults. One method to prevent constituent faults from compromising SoS performance is to increase the SoS's "resilience," a measure of the SoS's ability to cope with these faults and efficiently recover. Attempts to engineer improved resilience require a metric to measure resilience across different SoS architectures (network arrangements). In a previous work, the System of System Resilience Metric (SoSRM) was presented as a possible solution, but this new metric requires additional testing. This work examines the key question: "How can natural ecosystem characteristics be used to validate the SoSRM metric?" We hypothesize that the analysis of a test bed of generic ecosystems will produce SoSRM values that will positively correlate with a triangular trophic structure (wide base), validating SoSRM as a useful design metric. First principles for test bed creation are presented including biodiversity, trophic structure, and the role of detritus. SoSRM is measured for 31 case studies in a trophic structure test bed. Ecosystem network structure is quantified with graph theory. SoSRM correlates as expected with ecosystem network structure (r~2 =.5016, n=31), thus providing a validation of SoSRM as a design tool. As a final check, tests are conducted to ensure SoSRM is independent of trivial network characteristics (i.e. the number of nodes or links). By validating SoSRM, we provide a foundation for future work that focuses on increasing SoS resilience with biologically inspired design heuristics.