A root case analysis is performed to identify “what, how, and why something happened, thus preventing reoccurrence” (“Root Cause Analysis for Beginners.” Rooney, J. J. and Vanden Heuvel, L. N. Quality Progress 37, 2004, p. 45). This can be difficult when the problem being investigated is both subjective and transitory, which is often the case for a squeak-and-rattle issue in a vehicle.

Automotive customers are becoming more demanding, and vehicles are becoming quieter. This is an unbelievably bad combination when a vehicle has a squeak-and-rattle issue. Performing a root cause analysis (RCA) on an automotive squeak or rattle isn’t like other types of RCAs. Often, the investigator only knows “there is a sound coming from over there.” The problem may only be present under certain conditions, which adds to the complexity of the investigation. Removing a part to measure it may also change the conditions, resulting in the noise no longer being present. Removing a part may also change its geometry, making measurement data difficult to acquire.

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