How PM ROI is calculated
This calculator compares the cost of your current reactive breakdowns against the cost of a preventive maintenance program. Current reactive cost is breakdown frequency multiplied by average cost per breakdown. A PM program is expected to avoid a percentage of those breakdowns; the avoided cost minus the PM program cost is your net annual savings, and dividing by the PM cost gives the ROI.
The point is simple: a planned intervention almost always costs far less than the breakdown, lost production, and emergency repair it prevents, but only if the PM plan is actually followed.