P-F Curve

The P-F Curve is a graphical representation of an asset’s health over time that identifies the interval between an asset’s potential failure and its functional failure. Reliability Centered Maintenance (RCM) is a maintenance strategy developed around the understanding that failure is not always linear. The P-F Curve is a powerful tool for understanding RCM because it illustrates the behavior of an asset before and up to failure.

The P-F Curve marks two, important points: the potential failure point and the functional failure point.

Potential Failure: The “P” in P-F Curve refers to the potential failure point. This is the point where failure signs can first be detected.
Functional Failure: The “F” in the curve marks the functional failure of an asset. The functional failure is the point where an asset or piece of equipment actually fails.

The “P” and “F” point in the curve mark the P-F Interval: the time between when a failure can first be detected and when it is actually affecting operations.