A simpler daily-life example will help elucidate PDM (Predictive Maintenance for the benefit of first time readers).
Say your car has an oil temperature gauge, and an oil pressure gauge. For a while you’ve been noticing slightly higher-than-normal oil temperatures and lower-than-normal oil pressures. There is the more obvious likelihood that the oil quantity is insufficient. So you top up the oil quantity and take a general look-around and under the chassis to make sure there’s no visible signs of oil leakages. The gauges now indicate normal oil temperatures and pressures. However, after a while the problem recurs. What does that tell you? In simple terms, a trip to the mechanic is on the cards! You really don’t want to come to a situation where your car comes to a complete halt. For some strange reason the likelihood of this happening is highest when you most want to reach your destination! Or, worse, when you’re in the middle of evening rush hour!! I’ve heard all those stories from blokes complaining about their cars conspiring with them, right at the opportune moment! Nevertheless, conspiracies aside, what really prompted you to take your car to your mechanic? What prompted you to take preventive measures? The higher or lower than normal indications from the gauges in your car.
Predictive Maintenance is no different in that you are essentially taking preventive measures to rectify a component well before it’s complete failure, which in-turn could have an adverse affect on the entire system. In predictive maintenance you’re constantly gathering data on the functioning parameters of components and systems, and monitoring that data (active or discreet monitoring) at specific intervals to ensure smooth and correct operations.
If a small component of the system shows abnormal readings, through past experience with that component, we can tell approximately how many hours further before failure of that component. As an example, this ‘small’ component may actually have a larger role to play in the system than many others. Therefore, getting advance notice of it’s impending failure makes it very important to ensure the overall system continues to function normally and, if required, continuously.
This ability to pre-empt component performance over a wide range of operating parameters forms the core of Predictive Maintenance.
