You already worked out (or estimated) what reactive maintenance costs on this machine. This calculator asks one more question — how much would a real PM program cost to run — and compares the two.
PM program cost = (PM labour hours × PM rate) + PM parts/materials
Net savings = avoided cost − PM program cost
The U.S. Department of Energy's commonly cited figure is that reactive repairs cost roughly 3 to 5 times more than the same work done as scheduled maintenance — which is the underlying mechanism behind why a breakdown-reduction percentage translates into real dollars here.
Same CNC machine as the downtime cost example: $14,800/year in reactive maintenance cost today. A modest PM program — 20 hours/year at $65/hr plus $500 in parts — is expected to cut breakdowns by 40%.
- ASSUMPTIONThe reduction percentage is your estimate, not a measurement. Start conservative, and revisit it once you have a few months of real before-and-after data.
- SCOPEThis compares PM cost to avoided reactive cost only — it doesn't count extended machine life or delayed replacement, both real but longer-horizon benefits of PM.
- BASELINEShops doing almost no PM today typically see bigger gains than shops already keeping reasonable upkeep. Don't expect the same percentage if you're already disciplined about it.
- OVER-PMMore PM isn't automatically better — published research has found a meaningful share of PM tasks performed on equipment that didn't actually need it. Target your highest-risk machines first.
- HORIZONThis is a one-year snapshot. Run it again each year as your actual breakdown history changes, rather than treating one calculation as permanent.
Published research on this varies widely — some studies cite 12-18% overall maintenance savings from adopting PM, others cite $3 to $10 returned for every $1 spent, depending heavily on how neglected the equipment was to begin with. There isn't one true number, because the honest answer depends on your specific machines and failure history.
Rather than quietly picking a flattering default, this calculator asks you to supply your own estimate and shows exactly how sensitive the result is to that one number.