Maintenance activities typically focus on individual components (e.g., circuit breakers, switches, transformers). That’s a good way to organize the work, because different components have different maintenance needs. From a strategic point, however, this is not how you want to do it.
We maintain things to keep them from failing. From the component viewpoint, it’s a success when you can keep a transformer in service long past the recommended replacement date. But now you have a transformer that’s been accumulating the effects of age, making it a time bomb for failure. That’s where the problem comes in from a system viewpoint.
Suppose that old transformer is the supply for a critical production line. The risk that the line will go down is greater than it should be, because instead of maintaining that line as a system you tried to get the maximum life out of a component.
