Expert systems for safety-critical applications: theory, technology and applications

A knowledge base may contain no demonstrable errors or inconsistencies, and the programs which apply it may operate as intended, yet the advice given by an expert system may be sub-optimal or even unsafe. This problem of consequential safety is an inevitable consequence of attempting to build practical technologies on the basis of some current state-of-the-art in any field which is not fully understood. This paper is concerned with issues concerning the design of such systems whose advice may have implications for safety. It sets out the objectives and formal specification methods of a Rigorously Engineered Decisions (RED) project extending and applying symbolic decision theory.