P-F Curve on the Homefront

As a Maintenance and Reliability Consultant working with folks in all industries, I love it when I experience a scenario at home that directly ties to the concepts, principles, and philosophies we teach and consult on!

My wife Kathy (Operator) had been telling me (Maintenance) that she was hearing a strange noise coming from the front of her car while driving it. It was a noise that hadn’t been heard by her previously.

I went for a ride with her in the car and could not hear the noise she was referring to. I did pull both front wheels off for a visual inspection and could not see anything out of order, and I wasn’t able to hear any noise while spinning the wheels. I told her to let me know if it got worse.

This is the point of “Potential Failure” on the P-F Curve being brought to maintenance’s attention by the equipment operator, where previous maintenance activities haven’t detected the Potential Failure.

A month or two went by and she told me that the noise was getting louder and was even more noticeable when turning the car to the right. I went for another ride with her and I could now also hear the noise.

We are now moving down the curve towards “Functional Failure”.

Subsequent maintenance repairs determined the right front wheel bearing was failing and it was replaced. The left front wheel bearing was also replaced at the same time.

This is a great example of the equipment operator knowing if their equipment is operating correctly and promptly notifying maintenance when an abnormality is suspected!