A decision support framework for legacy systems integration

Legacy software systems are often the subject for analyses in attempts to affect modifications to extend their useful lifetimes. In particular, reengineering legacy systems or integrating legacy systems with new development and/or off-the-shelf software are areas in which effective software analysis is critical. When analyzing a software system, a range of system artifacts may be used. These artifacts may include a description of the system in natural language, some program design language, flow charts, object diagrams, as well as the system code. All of these artifact types can contain equivalent information at their specific level of abstraction. However, deriving information that is needed for reengineering or integrating a legacy system from each of these artifacts cannot be performed equivalently. For example, analyzing a poorly structured system with little or no design documentation is a particularly challenging problem. Software modeling using an abstract architecture representation as a common description vehicle, such as the Unified Modeling Language (UML) or some other technique, can “level the playing field” by creating representations of disparate systems at the same level of abstraction. This is of importance to reengineering efforts; it shows extreme promise for supporting and facilitating integration efforts between legacy and other systems. This dissertation therefore presents a methodology to express and manipulate (i.e. restructure) system architecture-level models, to evaluate the integratability of those models and to provide a prototype decision support system framework that demonstrates the use of the methods. This research contributes to the body of knowledge for software systems analysis, reengineering, and service oriented architecture component integration.