A Method for Systems Analysis and Specification with Performance, Cost and Reliability Requirements

In the past, space design activities mainly emphasized the system requirements. The available methods focused on functional aspects only. The cost was estimated at the end of the process. Recently, new design methodologies have been proposed. Among them, the design-to-cost (DTC) method was developed to include the cost as a parameter. In this work we propose an extension of the DTC method for systems analysis and specification. In other work we applied it to the design of a reaction wheel. Its basic components are described. General information on system development is related. The object-oriented approach is used as a modeling tool. Performance indexes are defined. A set of algebraic equations describes the cost behavior as a function of system parameters. Reliability is evaluated secondarily. The proposed model embodies many approaches to solve and/or optimize a problem with any level of complexity.