Learning from History: The Reliability of Experts and Expert Systems

Engineering design must be cost-effective over its complete life cycle and this necessitates a statistical approach to product and service reliability. A particular design therefore has a finite probability of failure during its lifetime and this has implications in terms of ensuring that design procedures, management of design, and operation and inspection are appropriate, effective and sufficient. Sophisticated expert system software packages have enabled wide access to rapid development to prototype and production stages. The expert knowledge encapsulated in such systems may be inadvertently used outside its intended application envelope, leading to unexpected and unwelcome failures. This paper highlights the role of failure analysis and fractography in the context of product reliability. It will present case studies illustrating typical structural reliability problems that highlight issues connected with the ‘reliability’ of experts in assessing the reasons for failure.