Demonstration Of Fuzzy Factors And Relationships For Strategic Availability Analysis

Few strategic decision-making tools are effective today in availability analysis. These tools adapt highly deterministic approaches, ignoring uncertainty and subjectiveness naturally existing when evaluating potential propulsion system technologies. Such approaches preclude the use of a rich source of knowledge available from subject matter experts. Introduced is the concept of "fuzzy" availability parameters for modeling uncertainty. Presented as environmental "fact", these statements are "fuzzified" by assigning linguistic values to statement value, importance, and confidence, altering relationships among parameters. Improved technologies in Influence Diagramming provide systematic approaches for collapsing models to precise, manageable parameters and relationships. The proposed approach allows a confidence-consideration of the results in a revised availability model. Technical objectives include modifying current Mil-Std 1388 model of operational availability, expanding model elements to include comprehensive factors, selecting factor units of measure and linguistic descriptors depicting various factor levels, developing environmental parameters defined by expert knowledge statements, demonstrating fuzzy set logic operations that combine factor parameters, developing a moderated factor value based on those operations, and demonstrating simulation trade-analysis with results. Phase I deliverables will be a complete availability model, measures for all factors, decision criteria, and demonstration trade analysis results of baseline and alternative propulsion technologies.