Supplier selection and evaluation are arguably one of the most critical functions for the success of an organization. Thus companies have increasingly considered better supplier selection approaches in order to attain the goals of low cost, consistent high quality, flexibility and quick response. In this paper, we present a measure of the overall reliability performance which is a weighted mean of the process capability indices of the reliability prediction characteristics of a supplier. This measure can be used both as a measure of supplier selection for the customer and as a measure for the self-diagnosis of the reliability prediction performance for the supplier.