Chris Weir — New Contributor

Author of the article series Beyond the Numbers: Human Reliability in Practice. The author's archive lists contributions to articles and episodes.

About Chris Weir

Chris is expanding his focus into Human Factors and Human Reliability Analysis. In his article series Beyond the Numbers: Human Reliability in Practice, he shares what he’s learning along the way, from practical techniques to real-world examples, showing how human-centred thinking can be woven into traditional reliability engineering tools and processes.

Chris also writes the Reliability Bites series, informed by the CRE Body of Knowledge, offering short, practical insights into core reliability topics and helping bridge certification concepts with real-world engineering practice.

by Chris Weir Leave a Comment

What do we really mean by “reliability”?

When people hear the word reliability, it’s often interpreted as meaning “zero failures”. While that’s understandable, it’s not what reliability engineering is really about.

The Certified Reliability Engineer (CRE) Body of Knowledge, produced by the American Society for Quality, defines reliability as:

“The probability that an item will perform a required function without failure under stated conditions for a specified period of time”

Crucially, each part of this definition needs to be clearly understood and agreed from the outset, particularly between customers and suppliers. Many reliability problems arise not because the definition itself is wrong, but because these elements are interpreted differently.

[Read more…]

by Chris Weir Leave a Comment

Integrating Human Factors with Traditional Reliability Techniques

In Part 1 of Beyond the Numbers, I reflected on why Human Factors matter in reliability engineering and how the human element of the system can be overlooked by traditional hardware-focussed approaches.
This article explores how Human Factors principles can be integrated into traditional reliability analyses such as Reliability Block Diagrams (RBDs), Fault Tree Analysis (FTA) and Failure Mode, Effects and Criticality Analysis (FMECA) and without reinventing the wheel or introducing additional complexity.

The short answer is that we are already doing much of this implicitly. Applying Human Factors principles makes those assumptions explicit and therefore visible, challengeable and open to improvement. [Read more…]

by Chris Weir Leave a Comment

Why Human Factors Matter in Reliability and Maintainability

For reliability engineers, numbers can be our comfort zone. Predictions, modelling, analysis and results, work that is rigorous, data-driven, and essential for complex systems – but does it always tell the full story?

Recently completing Level 1 of the CIEHF Cross-Sector Learning Pathway has led me to consider system reliability in a different light. Technical performance alone does not guarantee success and to truly understand reliability, we must also account for the human component – the operators, maintainers, and decision-makers whose actions are inseparable from system outcomes.

[Read more…]