The Evolution and History of Reliability Engineering: Rise of Mechanistic Reliability Modeling

To address the risk and reliability challenges in both private and regulatory sectors, the reliability engineering discipline has gone through a number of transformations during the past few decades. This article traces the evolution of these transformations and discusses the rise of mechanistic-based reliability modeling approaches in reliability engineering applications in recent years. In this paper we discuss the ways reliability models have progressively become more practical by incorporating evidence from the real causes of failure. Replacing constant hazard rate life models (i.e., exponential distribution) with other distributions such as Weibull and lognormal was the first step toward addressing wear-out and aging in the reliability models. This trend was followed by accelerated life testing, through which the aggregate effect of operational and environmental conditions was introduced to the life model by means of accounting for stress agents. The applications of mechanistic reliability models were the logical culmination of this trend. The physics-based (or mechanistic-based) reliability models have proven to be the most comprehensive representation, capable of bringing many influential factors into the life and reliability models of the components. The system-level reliability assessment methods currently available, however, seem to have limited capabilities when it comes to the quantity and quality of the knowledge that can be integrated from their constituent components. In this article, past and present trends as well as anticipated future trends in applications of mechanistic models in reliability assessment of structures, systems, components and products are discussed.