Life cycles in Software and Knowledge Engineering : a comparative review. Michael Wilson, David Duce Informatics Dept., Rutherford Appleton Laboratory Dan Simpson Dept. of Computer Science, Brighton Polytechnic. ABSTRACT Developments in software engineering have led to models of the system life cycle incor- porating the use of prototyping and formal methods of program verification. These are becoming supported by integrated project support environments and permit the planning and monitoring of software development projects. In contrast, Knowledge Based Systems (KBS) are developed using informal views of the system life cycle. Tools have been developed to support some stages of the life cycle in an undisciplined manner. The commercial use of KBS needs development projects to be planned and monitored. This requires methods and tools based on systematic life cycle models to be established for KBS. This paper reviews the current state of life cycle approaches to software engineering and KBS development projects in order to provide a direction for the development of methodical KBS life cycle models.