Last, but certainly not least on the list of reliability tools, is Root Cause Analysis. It seems unlikely that an organization will be successful in improving reliability using any of the other tools or techniques, without first mastering Root Cause Analysis (RCA). The important characteristics are rigor and discipline. RCA provides an organization with the rigor needed to adhere to a structured process, and the discipline needed to gather and use appropriate and accurate data.

The importance of being able to find the true root cause cannot be overemphasized. Even large, well-established organizations, that are confident in their analytical capabilities, frequently do not have the ability to find root cause or the self-reflection needed to recognize this limitation.

Returning to the hierarchy that was described earlier, one has to understand the true Failure Mode to identify the actual Failure Mechanism. Beyond that, one needs to understand the Failure Mechanism to begin to drill down and identify the various levels of root cause.

When pursuing the root cause, the "physical cause" will always appear first and be most evident. Physical systems and components cannot speak for themselves so they are always first to be blamed. How many times have you heard, "That old thing, it always breaks down?"

No physical device ever designed itself, operated itself, inspected or maintained itself, so a human has to be involved in the failure at some point. It is important to emphasize that humans are involved in creating the causes of failure,...