Reliability enhancement methodology and modelling: the REMM project

Customers demand reliable products and such demands are reflected in the product specification and requirements documents. Indeed, contractual obligations are being introduced to ensure that the supplier meets the cost of unreliability. Thus, equipment suppliers must design products to perform reliably for the required product life. Moreover suppliers must provide sufficient evidence that their product will meet reliability requirements. This evidence is termed the reliability case. The main instigator for the use of the reliability case is the British Ministry of Defence (MoD) under the guise of Defence Standard 00-42 Part 3 but the concept is also becoming accepted in the commercial field as one of the key criteria for selecting products. This paper describes the work carried out under a collaborative project funded by the UK Department of Trade and Industry (CARAD) entitled reliability enhancement methodology and modelling (REMM). More specifically it will concentrate on demonstrating the methodology in the form of providing the necessary guidance for building a reliability case. It will also discuss the challenges associated with design for reliability and demonstrate how the REMM tool will encourage designers to consider what might go wrong. The REMM tool encompasses a reliability assessment model and this paper will describe and discuss the advantages of this Bayesian model with particular reference to decision making aspects during the design stage of a project.