Expert Elicitation for Reliable System Design

This is a short discussion article about the comprehensive review paper by Bedford et al o n expert elicitation for reliable systems. Our article highlights especially the benefits of using Bayesian networks and also raises a number of issues that follow on from the review paper. The paper " Expert elicitation for reliable system design " by Bedford, Quigley and Wallis is timely and significant for three reasons: 1. It addresses the importance of expert elicitation in systems design and the statistical and practical challenges faced when trying to use expert judgements in a way that is consistent with established approaches based on statistical reliability testing. 2. It rightly focuses our attention on the need for a holistic approach to reliability evaluation that goes beyond analysis of single projects to also include information from " softer " sources such as design and operational use. 3. It recognises the emerging importance of Bayesian methods in providing the " uncertainty calculus " to combine evidence from experts with statistical