Assessing Product Reliability from Warranty Data

Warranty data can be a useful, accurate, and timely information source for monitoring the reliability of a product. At Cummins Engine Company a warranty based reliability information system was developed for diesel engines that has the capability to 1) evaluate the reliability of engines and their components, 2) compare the reliability performance of engines and components to goals and prioritize those areas needing improvement, and 3) detect changes in the warranty claims pattern of engine components to provide early warning of potential problems.

This paper will describe this warranty data system with emphasis on the analytical tools used to perform the above activities. Although many of the examples refer to diesel engines, the general concepts apply to the use of warranty data for many types of products.