Reverse Engineering of Computer-Based Navy Systems

The �nancial pressure to meet the need for change in computer-based systems through evolution rather than through revolution has spawned the discipline of reengineering. One driving factor of reengineering is that it is increasingly becoming the case that enhanced requirements placed on computer-based systems are overstressing the processing resources of the systems. Thus, the distribution of processing load over highly parallel and distributed hardware architectures has become part of the reengineering process for computer-based Navy systems. This paper presents an intermediate representation �IR� for capturing features of computerbased systems to enable reengineering for concurrency. A n o vel feature of the IR is that it incorporates the mission critical software architecture, a view that enables information to be captured at �ve levels of granularity: the element�program level, the task level, the module�class�package level, the method�procedure level, and the statement�instruction level. An approach to reverse engineering is presented, in which the IR is captured, and is analyzed to identify potential concurrency. T h us, the paper de�nes concurrency metrics to guide the reengineering tasks of identifying, enhancing, and assessing concurrency, and for performing partitioning and assignment. Concurrency metrics are de�ned at several tiers of the mission critical software architecture. In addition to contributing an approach to reverse engineering for computer-based systems, the paper also discusses a reverse engineering analysis toolset that constructs and displays the IR and the concurrency metrics for Ada programs. Additionally, the paper contains a discussion of the context of our reengineering e�orts within the United States Navy, b y describing two reengineering projects focused on sussystems of the AEGIS Weapon System.