A model for reengineering legacy expert systems to object-oriented architecture

摘要

The migration of existing systems to object-oriented technology is becoming increasingly important. In this paper, a reengineering model is presented. The goal of the model is to provide a comprehensive method to reengineer non object-oriented systems into object-oriented architecture. The model consists of three main processes: Reverse engineering, merging, and object-oriented development. Reverse engineering extracts requirements and knowledge from an existing software system and redocuments the system. In the merging process, recovered requirements and knowledge from the reverse engineering process are merged with new requirements and knowledge. The merging process removes redundancy, checks for inconsistency, and detects incompleteness. In the object-oriented development, a reengineered system is developed using an object-oriented software development method. This research demonstrates that successful reengineering to object-oriented architecture can be achieved by using requirements and knowledge from the original system as a basis for developing the object-oriented system. The model proved to be useful where a paradigm shift is needed. The effectiveness of the model was demonstrated by converting a legacy non object-oriented software system (implemented in C) into an object-oriented system (implemented in Smalltalk). A set of tools was built to support the model. We also identify guidelines that facilitate the transformation of legacy software systems into object-oriented systems.