Root Cause Failure Analysis Using Physics of Failure Factors and Failure Cause Mechanism Guidewords


This equipment root cause failure analysis technique is used to list all the possible root causes of a component’s failure. It applies Physics of Failure science to identify the conceivable ways a part could fail while in service. Once the list of potential failure causes is developed, then each cause is considered and investigated as to whether it did, or it did not, play a part in the failure. A free download of the Physics of Failure Factor Analysis (POFFA) standard guidewords table used to start an equipment related root cause failure analysis (RCFA) is provided.

Keywords: root cause analysis, RCA, root cause failure analysis, RCFA, Physics of Failure Factor Analysis (POFFA), equipment failure analysis guidewords

Organizational problems this article helps you to address:

      • Identify all likely equipment failure root causes to investigate and eliminate
      • Consistently apply a simple equipment failure root cause identification technique
      • A universal way to proactively remove failure root causes to make equipment reliable

Often, we are asked for guidance on how to find and address the root causes of operating plant and equipment failures. A recent enquiry is noted below.

“Our pH probes need to be replaced too frequently in the wastewater treatment plant. I am researching possible reasons. Can you think of an instance when a water treatment plant would electrostatically damage a probe?”

The advice to the enquirer was to start the root cause analysis (RCA) investigation by using the Physics of Failure Factors and Failure Cause Mechanisms Guidewords table shown in the image below. An image with the expanded view of the ‘Electronic / Electrical Degradation Conditions’ column that is relevant to pH probe failure from electrically related issues is shown under the table image. They use the list of failure cause mechanisms to begin the RCA by identifying all conceivable causes of their specific failure event.


Every conceivable cause of the component’s failure listed in the applicable columns of the table are identified. One by one each possible failure mechanism is investigated for evidence of its presence and influence in the failure event. When related failure mechanisms are confirmed, then the RCA progresses onto addressing the cause and implementing a solution to prevent the failure recurring.

You can click this link and download a free Excel version of the guidewords table for you to use when starting an equipment failure related root cause analysis: Physics of Failure Factors and Failure Cause Mechanisms Guidewords Table.

An explanation of this science-based RCA approach is in the Industrial and Manufacturing Wellness book.

Mike Sondalini
PWWEAM System-of-Reliability
16 May 2022