A systematic method of reusing objects extracted from legacy systems

Billions of dollars are spent each year on computer software. Much of this effort is spent on creating and testing new source code. In order to save money, increase productivity, and improve reliability, academic and industrial institutions have put forth a lot of effort on software reuse. Identifying, extracting and reengineering software components that implement abstractions within existing systems is a promising cost-effective way to create reusable assets and re-engineer legacy systems. This paper summarizes our experiences with using computer-supported methods to develop a software architecture to support the re-engineering of the Janus Combat Simulation System. In this effort, we have developed an object-oriented architecture for the Janus and validated the architecture with an executable prototype. In this paper, we propose methods to facilitate the reuse of the software component of these systems by recovering the behavior of the systems using systematic methods, and illustrate their use in the context of the Janus System.