Coordination specification for distributed optimal system design using the χ language

Optimal design problems of large-scale and complex engineering systems are typically decomposed into a number of smaller and tractable subproblems. Analytical target cascading (ATC) is a methodology for translating overall system design targets to individual specifications for the subsystems and components that make up the system based on a hierarchical partition. We propose to use the χ language and software tools to specify and implement the coordination of the analytical target cascading process. ATC is implemented as parallel processes that exchange data via channels, which represent the links between the subproblems. The process specifications define how individual processes communicate with other coupled processes. We show the advantages of χ for coordinating the ATC process by means of an illustrative example, and demonstrate that different coordination strategies can be implemented and evaluated efficiently