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Analyzing Failure
ОглавлениеMost people avoid analyzing the failure altogether because many a time it is emotionally unpleasant and can chip away at our self‐esteem. Another reason is that analyzing organizational failures requires inquiry and openness, patience, and a tolerance for causal ambiguity. Hence, managers should be rewarded for thoughtful reflection. That is why the right culture can percolate in the organization.
Once a failure has been detected, it’s essential to find out the root causes not just relying on the obvious and superficial reasons. This requires the discipline to use sophisticated analysis to ensure that the right lessons are learned and the right remedies are employed. Engineers need to see that their organizations don’t just move on after a failure but stop to dig in and discover the wisdom contained in it.
A team of leading physicists, engineers, aviation experts, naval leaders, and even astronauts devoted months to an analysis of the Columbia disaster. They conclusively established not only the first‐order cause – a piece of foam had hit the shuttle’s leading edge during launch – but also second‐order causes: A rigid hierarchy and schedule‐obsessed culture at NASA made it especially difficult for engineers to speak up about anything but the most rock‐solid concerns.
Motivating people to go beyond first‐order reasons (procedures weren’t followed) to understanding the second‐ and third‐order reasons can be a major challenge. One way to do this is to use interdisciplinary teams with diverse skills and perspectives. Complex failures in particular are the result of multiple events that occurred in different departments or disciplines or at different levels of the organization. Understanding what happened and how to prevent it from happening again requires detailed, team‐based discussion, and analysis.
Here are some common root causes and their corresponding corrective actions:
Design deficiency caused failure → Revisit in‐service loads and environmental effects, modify design appropriately.
Manufacturing defect caused failure → Revisit manufacturing processes (e.g. casting, forging, machining, heat treat, coating, assembly) to ensure design requirements are met.
Material defect caused failure → Implement raw material quality control plan.
Misuse or abuse caused failure → Educate user in proper installation, use, care, and maintenance.
Useful life exceeded → Educate user in proper overhaul/replacement intervals.
There are various methods that failure analysts use – for example, Ishikawa “fishbone” diagrams, failure modes and effects analysis (FMEA), or fault tree analysis (FTA). Methods vary in approach, but all seek to determine the root cause of failure by looking at the characteristics and clues left behind.
Once the root cause of the failure has been determined, it is possible to develop a corrective action plan to prevent recurrence of the same failure mode. Understanding what caused one failure may allow us to improve upon our design process, manufacturing processes, material properties, or actual service conditions. This valuable insight may allow us to foresee and avoid potential problems before they occur in the future.