Seminar: Expert judgement informed reliability growth models and the allocation of reliability tasks

Event Date: 13 February 2015

Speaker -  Kevin Wilson

Friday 13 February: 1.30-2.30pm

Room 863 (Blackett room) Graham Hills Building

Abstract - There are many mathematical models in the literature for how a system’s reliability grows during development as a result of the Test, Analyse and Fix (TAAF) cycle. Most are based on convenient parametric forms and are extensions of simple models such as Poisson Processes. Often we can find one of these parametric models which fits our data well. However, parameters in such models are typically not observable and so eliciting a subjective prior distribution, which is often desirable due to a lack of observed data, is a challenging task. Further, engineers can be rightly sceptical of models based on parameters with no physical interpretation.

In this talk we present a model for a reliability growth programme developed with engineering experts in the aerospace industry. All of the model parameters can be elicited from observable quantities and so priors can be specified directly. The model is used to identify an optimal subset of reliability tasks from a large number based on targets for cost, time on test and system reliability. The optimal subset is identified by maximising the prior expectation of a multi-attribute utility function.

Published: 10 February 2015