SoS Meta-architecture Assessment by Dual Application of Rule Based Fuzzy Inference Systems

In the early stages of system of systems (SoS) meta-architecture concept development, it is greatly beneficial to have a formal method of architecture assessment to ensure compliance to stakeholder needs and requirements. Key performance attributes (KPAs) and key functional attributes (KFAs) are linguistic terms that represent the non-functional and functional requirements of the architecture. KPAs and KFAs can be assessed and converted into numeric values that can be used as fuzzy inputs to Mamdani-type rule based fuzzy inference systems (MRBFIS) to make fuzzy assessments of SoS meta-architecture concepts. This paper details an application of an assessment model featuring the integration of two separate MRBFISs; each with five inputs, five membership functions (MFs), twenty five If-Then rules, and a single output that is determined by the fuzzy rule base. Each unique MRBFIS used in the assessment was developed using the MATLAB Fuzzy Logic Designer application. The numeric outputs of each MRBFIS were then combined to provide an integrated KPA and KFA total architecture assessment score. The assessment model detailed in this paper provides a formal method of architecture assessment to be used in conjunction with trade space exploration, systems scoping, and the concept generation phase. This assessment model may help prevent costly project failures, system ambiguity late in development, unacceptable risks, cost overrun, and the inability to develop critical systems.