Author Archives: weibuller

What is Reliability Engineering?

The general public, and even many engineers for that matter, are not familiar with the field of Reliability Engineering, so I thought this first post should provide the reader with a description of the discipline and an explanation of what a Reliability Engineer might be called-upon to do.

Reliability Engineering consists primarily of recognizing how and why “things” fail (in terms of the loss of function of the “thing” and the physics of the failure mechanism involved when it does fail) and using specialized statistical techniques to mathematically characterize the failure behavior. The mathematical relation between usage (operating time, cycles, mileage, calendar time, etc.) and the probability of failure of the “thing” can be used for a variety of purposes, including but not limited to:

  • Estimating the life span of a product
  • Predicting the number of product returns within a warranty period
  • Forecasting the workload in a repair shop
  • Performing a safety assessment of a system
  • Determining the probability that a system will (or will not) fail during a given period

A Reliability Engineer will often be brought into design reviews (for new or modified systems or components) to assess weaknesses or inadequacies in the design of a system or component itself, or with respect to how it will interact with other systems and components. This requires an in-depth understanding of how the system or component works (its physical operation and the functions it provides/performs), how various parts of the system or component can degrade in the presence of operating loads or stresses (under normal conditions as well as during extreme use conditions), and how that degradation can manifest itself and affect the normal operation of not only that system or component, but other systems and components that rely on them.

This level of expertise — in how various systems and components are designed, how they function, how they may interact with other systems and components, how they may degrade, and how that degradation could affect other systems and components — means that a typical Reliability Engineer first needs to be a relative expert in another engineering discipline, such as Mechanical, Electrical, or Aerospace engineering. Reliability Engineering then become a specific area of specialization for an engineer experienced in another discipline and typically requires additional training and certification in various reliability tools and techniques.

In future posts, I’ll talk about various tools and techniques used by Reliability Engineers to perform their analyses, as well as resources available on the Web.

Thanks for visiting!