A structured methodology for developing production systems

Issues such as project management, documentation, and maintenance, typically associated with large traditional software development projects have recently become important concerns in the development of expert systems. The authors describe a structured methodology for the development of production rule-based expert systems. The methodology prescribes a procedure to help knowledge engineers manage the complexity of a knowledge base by viewing rule and parameter dependencies at successive levels of abstraction. Parameters are clustered into modules, in a manner analogous to functional decomposition in structured design. The modularization thus obtained provides three significant benefits: ease of subsequent knowledge base maintenance, enhancement of code reusability, and support for knowledge base verification. The visual tools used by the methodology facilitate communication between knowledge engineers and experts and provide ongoing documentation of the system.