PERFORMING A FAILURE SCENE INVESTIGATION

As head of Noria's failure investigation group, I've led many interesting studies in search of failure root causes and remedies.

- 

These include missile system failures, highway accidents, helicopter crashes, and turbine-generator wrecks. Most of these nearly 100 investigations were substantially hampered by errors made in collecting and preserving evidence.

We know that when critical failures occur, every effort should be made to prevent repeat performances. Yet, without an intervention to remove the underlying root cause, a recurrence is almost guaranteed.

It stands to reason that maintenance organizations should consider failure investigations as seriously as they do the repair activities needed to return a machine to service. Yet all too often, once production has been restored, the urgency and memory of the failure begins to fade.

We've published extensively on the importance of root cause analysis (RCA) and the steps needed to carry out an RCA. This column will not address these well-documented procedures but instead focuses on the equally important task of preserving and collecting evidence.

After all, it is this evidence that serves as the essential raw material used in the RCA processes. The quality and completeness of this evidence (raw material) is arguably the central factor that determines the precision of the delivered result (the root cause and RCA end product).

Sadly, by the time I get a phone call to participate in an RCA, there is usually only a scintilla of evidence remaining. Perhaps there are a few fragments of a broken bearing or the shelled-out remains of a failed pump. In other cases, there might be photos of the crime scene taken by an alert technician. Of course, there is plenty of anecdotal evidence and personal theories from people who arrived first on the scene. But when it comes to collecting quality data and preserving physical evidence, what's available is usually pretty skimpy. My advice on preserving evidence is as follows:

What to Do When an Impending Failure is Suspected