Event-based functional decomposition.

Functional decomposition is the process of resolving a functional relationship into its constituent parts in such a way that the original function can be recomposed from those parts by functional composition. Perfect decomposition requires the obtained constituent parts to be non-interacting components and easier to conceive, understand, program, and maintain. However, how to decompose a complex system and ensure the correctness of such a decomposition approach usually relies on some informal principles. In this paper, we present a new and automatic decomposition approach for functionalities. We first show the correctness of the functional decomposition in terms of weakly termination in theory and then discuss the automation method of the functional decomposition. The approach can automatically decompose a system into independent subsystems which may be independently developed and deployed. Finally, we develop an algorithm. A case study demonstrates these results.