PM compliance is the percentage of scheduled preventive maintenance tasks that are actually completed within their required time or usage window, calculated as (PMs completed on time ÷ PMs scheduled) × 100.
It is one of the most-watched KPIs in maintenance management because a preventive maintenance schedule that exists on paper but isn’t actually executed on time delivers none of its intended reliability benefit — a low PM compliance rate is usually the earliest warning sign that a maintenance operation is sliding back toward reactive firefighting.
Calculating PM compliance
The basic formula: PM Compliance % = (Number of PMs completed on time ÷ Number of PMs scheduled) × 100
“On time” typically means completed within a defined grace window around the due date — for example, a monthly PM might be considered compliant if completed within 3-5 days of its due date, not only on the exact day. Organizations set their own grace windows based on how much drift is tolerable for a given asset class; a fire-suppression inspection has a much tighter tolerance than a routine lubrication task.
A team with 200 PMs scheduled in a month that completes 170 of them within the grace window has a PM compliance rate of 85%.
Why PM compliance is the metric that catches problems early
Other maintenance KPIs — MTBF, MTTR, unplanned downtime — are lagging indicators. They tell you a failure already happened. PM compliance is a leading indicator: it tells you whether the work that’s supposed to prevent failures is actually getting done, often weeks or months before a compliance gap shows up as a breakdown.
A team can look healthy on lagging metrics for a while even as PM compliance quietly slips, because reliability effects of skipped maintenance compound with a lag. By the time MTBF starts dropping, the PM backlog that caused it may have been building for months.
Common causes of low PM compliance
- Understaffing relative to PM volume — the maintenance team physically doesn’t have enough hours to complete the PM library as scheduled
- Poor PM scheduling logic — too many PMs clustered on the same days or same technicians, creating artificial bottlenecks
- Reactive work crowding out planned work — emergency repairs constantly bump scheduled PMs to the next day, and the backlog never clears
- PM library bloat — too many low-value PMs on assets that don’t need that level of attention, diluting technician time away from PMs that matter
- No visibility into what’s overdue — without a dashboard, PMs silently slip past their due date and nobody notices until something breaks
PM compliance and maintenance backlog
PM compliance and maintenance backlog are closely related but distinct: PM compliance measures whether preventive work got done on time, while maintenance backlog is the broader pool of all outstanding work — reactive repairs, inspection findings, and overdue PMs — that hasn’t been closed out yet. A growing backlog is often both a cause and a symptom of falling PM compliance: as the backlog grows, technicians spend more time firefighting the backlog and less time on scheduled PMs, which in turn adds more overdue PMs to the backlog.
Tracking PM compliance in a CMMS
A CMMS tracks PM compliance automatically once work order management captures scheduled due dates and actual completion dates for every PM. Most platforms surface this as a rolling percentage on a supervisor dashboard, broken down by technician, asset class, or site — which is what makes it possible to catch a compliance slide before it turns into a reliability problem.
Related terms
PM compliance measures execution against a preventive maintenance schedule, is tracked through work order management, and — left unaddressed — eventually shows up in worsening MTBF trends.