Two kinds that do not cost the same
- Unplanned (the breakdown): the equipment stops and someone has to rush out. It is expensive, unpredictable and the customer notices.
- Planned: an inspection finds an anomaly and the repair is scheduled before the equipment breaks. It usually costs far less than the first kind.
Much of the value of a preventive plan lies right there: turning unplanned corrective work into planned corrective work.
When corrective is the right strategy
For low-criticality equipment, whose failure stops nothing and which is quick and cheap to replace. A light fixture does not need a maintenance plan: it needs someone to change it when it burns out.
The usual mistake
Believing the goal is “zero corrective work.” It is not. The goal is to decide which equipment goes to corrective and which does not, instead of reacting without a plan. And to track the ratio of corrective to preventive work to see if that decision is working.