Some of the basic ideas of general systems theory include the propositions that, in general, every system consists of subsystems and that every subsystem is itself a system. It therefore follows that any system can be decomposed into its component subsystems and that each of those component subsystems can be further decomposed into their subsystems, and so on. Systems analysts have long utilized this property of systems in functional decomposition, an analytical tool that assists in efforts to break down complex systems into comprehensible subunits that can be analyzed and understood separately as part of the analysis and design phase of systems development. This paper deals with the mathematical modeling of decomposition activity in order to automate it.

This concept is not surprising. CASE tools have recently emerged as systems development tools that support automation of the systems development process. Automating the decomposition activity of systems analysis is a theoretically appealing and intuitively attractive next step in the development of CASE technologies.

This research unquestionably represents an interesting and important initial step. For example, the authors have developed a system that actually does decomposition based upon a series of rules that they explain in their paper. Several interesting examples of decompositions done by this system are presented.

It remains to be seen whether this kind of automated tool can achieve the levels of flexibility, variety, and richness of decomposition analysis that an experienced human analyst can achieve. I have little doubt that an automated approach to decomposition will someday become commercially feasible. This paper is therefore a must read for systems analysts and their managers, especially if they are involved in CASE technologies.