PLEXACT: an architecture & design of a knowledge-based system for information systems development

Abstract

This paper discusses the architecture and design of an expert system PLEXACT, (PLEXsys in ACTion), which can be used to assist users in defining their information requirements and to analyze the consistency and integrity of the requirements. PLEXACT is different from other system analysis languages and tools because of its active participation in the requirements elicitation process and its dynamic system architecture which is adaptable to different system development settings.Current system analysis methodologies are first reviewed and evaluated. An intelligent system development tool that can remedy the disadvantages of the current approaches is described. The knowledge needed for information systems development is identified and representations of this knowledge are discussed. An object-oriented and communication-based architecture, called PLEXACT, is proposed. PLEXACT is a configurable system architecture which can support expert system building for information system development. The kernel of PLEXACT includes: (1) Development Coordinator: coordinates different expert system models to solve the system problems and guide the development process. Development Coordinator consists of four components: User Modeler, Project Controller, Problem Analyzer, and Development Knowledge Base and Data Base; (2) Information Systems Modeler: builds information system development theories, methods, and tools into expert system models to capture multiple perspectives of a system at different level of abstraction. Models can work together by specifying their coupling information to Model Creator. Information Systems Modeler consists of Model Creator, Model Instantiator, System Analyst and Designer, Model-based Learner, and Modeling Knowledge Base and Data Base. Current research in knowledge-based system development tools and some implementation issues of PLEXACT are also discussed.