Dealing with Fractional Failures and Survivors in Data Analysis of Reliability Engineering

Authors of this paper summarize and discuss various scenarios in real world reliability engineering practice where fractional failures and fractional survivors can be encountered. Examples are given to illustrate their manifestation, failure classification and fractional failure determination, data entry format, life distribution parameter estimation, reliability quantification, and field risk prediction. It is the authors' belief that fractional failure will become a norm, instead of an exception, due to various reasons. They include, but are limited to: the nature of failure initiation, development, and manifestation, effectiveness of corrective actions, failure-physics based identification of the sub-healthy condition using parametric degradation analysis techniques, failure analysis resource and capability limitation, etc. It is hoped that this paper will be beneficial to a wide audience including reliability engineers, theorists, and management.