This paper presents a method to assess the reliability of products under development. The proposed methodology allows for the use of various sources of information commonly found in the development stages of a product, such as field or warranty data (failure rates), test data and subjective evidence (engineers/operators' opinions about the impact of design changes on the product's reliability). The method also allows for the incorporation of evidence of previous revisions of the same product or even information about products that are only similar to the one under investigation. The proposed methodology is illustrated through an example of the reliability assessment of high power X-ray tubes, which confirms that the reliability assessment of a new design before the actual testing of units containing the proposed design modifications offers the manufacturer a relevant source of information upon which to base decisions about the effective implementation of the design modifications.
reliability; product development; bayes' theorem
