You build a preventive maintenance schedule. You assign the work orders. At the end of the month, you discover that only 62% of those PMs actually got done. The other 38% were skipped, deferred, or forgotten. The machines that missed their PMs are now ticking time bombs, running with unchecked wear, low lubricant, or deteriorating components that will eventually cause a breakdown.
PM compliance measures the percentage of scheduled preventive maintenance work orders that are completed on time. It is one of the simplest and most revealing maintenance metrics. A high PM compliance rate means your maintenance team is executing the plan. A low rate means the plan exists on paper but not in practice.
This metric matters because preventive maintenance only works when it gets done. A perfect PM schedule that is only 60% executed is less effective than a basic PM schedule that is 95% executed. Consistency beats complexity every time.
The PM Compliance Formula
The formula is straightforward:
PM Compliance (%) = (Number of PMs Completed On Time / Number of PMs Scheduled) x 100
"On time" is the critical phrase. A PM that was due on March 5th and completed on March 20th is not compliant, even though it was eventually done. You need to define your compliance window: most plants use a window of plus or minus 10% of the PM interval. For a monthly PM, that means within 3 days before or after the due date. For a weekly PM, within 1 day.
Worked Example
Your plant had 120 PMs scheduled for March. Your team completed 108 of them within the compliance window. The other 12 were either skipped (5), completed late (4), or still open at month-end (3).
PM Compliance = 108 / 120 x 100 = 90%
That 90% puts you in the "good" range. But those 12 missed PMs represent equipment that did not receive the care it was supposed to get. If one of those missed PMs was a bearing inspection on a critical pump, and that bearing fails next month, the cost of the missed PM is the full cost of the unplanned breakdown: emergency repair, lost production, damaged components, and overtime labor.
What Good Looks Like
Industry benchmarks for PM compliance:
| PM Compliance Level | Range | Typical Plant Characteristics |
|---|---|---|
| Poor | Below 70% | Reactive maintenance culture. PMs are the first thing dropped when emergencies happen. Chronic equipment problems. High breakdown rate. Maintenance team constantly fighting fires. |
| Needs improvement | 70-85% | PM program exists but is inconsistently executed. Some areas are well-maintained, others are not. Reactive work still dominates the maintenance mix. |
| Good | 85-95% | PM program is well-managed. Planned work is protected from reactive interruptions most of the time. Equipment reliability is improving. Breakdowns are decreasing year over year. |
| Excellent | Above 95% | Disciplined maintenance organization. Reactive work is minimal. Strong planning and scheduling function. High equipment reliability. This level is achievable but requires a mature maintenance process. |
The target for most plants should be above 90%. That is the threshold where PM programs start delivering consistent reliability improvement. Below 85%, you are doing enough PMs to feel busy but not enough to actually prevent failures.
Plants that consistently run above 95% PM compliance typically have 50-70% fewer unplanned breakdowns than plants below 70%. The connection is direct: if you consistently perform the maintenance that prevents failures, failures decrease.
12 Common Reasons for Low PM Compliance
If your PM compliance is below 85%, one or more of these issues is the cause. They are listed roughly in order of how often we see them.
1. Emergency work displaces planned PMs
This is the most common reason. A machine breaks down, and the technician assigned to a PM gets pulled off to handle the emergency. The PM gets deferred. Next week, the same thing happens. A reactive maintenance culture makes PM compliance nearly impossible because breakdowns always take priority.
The cruel irony: the breakdowns that displace PMs are often caused by previously missed PMs. It is a self-reinforcing cycle. The only way to break it is to protect PM time aggressively.
2. Too many PMs on the schedule
Some plants create PM schedules that are physically impossible to complete with available labor hours. If your schedule calls for 800 PM hours per week and your available maintenance labor is 600 hours, you will never reach 100% compliance. Audit your PM program for tasks that are unnecessary, duplicated, or set at too-frequent intervals. RCM principles can help you identify which PMs are actually worth doing.
3. Equipment not released by operations
The PM is scheduled, the technician is ready, but the machine is running and operations will not release it. This is a coordination problem. The weekly maintenance schedule should be agreed to by both maintenance and operations. When operations commits to releasing equipment at a specific time, they need to follow through.
4. Parts not available
A PM calls for replacing a filter, gasket, or belt, but the part is not in stock. The technician cannot complete the PM. Good job planning includes checking parts availability before scheduling. If the parts are not in stock, either order them in time or reschedule the PM.
5. PM tasks are poorly defined
If a PM work order says "inspect pump" with no further detail, the technician does not know what to inspect, what to look for, or what measurements to take. Poorly defined PMs get done superficially (check the box without actually doing meaningful work) or get deferred because the technician is unsure what is expected.
6. No dedicated PM time in the schedule
If PM work competes with all other work for technician time, it will always lose to more urgent reactive jobs. Best practice: block 30-40% of available maintenance labor hours specifically for PM execution and protect that time.
7. Technicians do not see the value
If technicians believe the PMs are busywork that does not actually prevent failures, they will not prioritize them. This happens when PM tasks are outdated, not based on actual failure modes, or have never been reviewed since they were first created. Review PM tasks annually with the technicians who do the work and adjust based on their feedback and actual failure data.
8. Poor scheduling
PMs are dumped into the system with due dates but no consideration of labor availability, equipment availability, or workload balancing. You end up with 40 PMs due on the same day and 3 technicians to do them. Spread the workload evenly across the month and across the week.
9. CMMS data quality issues
The CMMS shows PMs as "overdue" that were actually completed but not closed in the system. Or PMs are generated for equipment that no longer exists. Or intervals are wrong. Dirty data makes your compliance number unreliable and makes it hard to trust the schedule. Clean your CMMS data regularly.
10. Supervisor does not track or enforce compliance
If nobody reviews PM completion weekly and holds the team accountable, compliance drifts. PM compliance should be reviewed every Monday morning: what was scheduled last week, what got done, what did not, and why.
11. PM frequency is too high
Some PMs are set at weekly intervals when monthly would be sufficient, or monthly when quarterly is appropriate. Overly frequent PMs waste labor hours and crowd the schedule. Use failure data and condition monitoring to set appropriate intervals.
12. No consequences for non-compliance
If missed PMs have no follow-up, no investigation into why they were missed, and no corrective action, the message to the organization is that PMs are optional. They are not optional. They are scheduled work with due dates, and missing them should trigger the same attention as a missed production order.
How to Track PM Compliance
Tracking PM compliance requires data discipline. Here is a practical approach.
Data source
Your CMMS is the primary data source. Every PM work order should have a scheduled date (or a compliance window), a completion date (or status), and a priority code. If you are not using a CMMS, you can track with a spreadsheet, but a CMMS is strongly recommended for any plant with more than 50 pieces of equipment.
Compliance window
Define what "on time" means. The most common approach is a window of plus or minus 10% of the interval. For a 30-day PM, the window is Day 27 to Day 33. Completing the PM on Day 34 counts as late (non-compliant). Some plants use fixed windows (e.g., plus or minus 3 days for all monthly PMs). Pick one method and apply it consistently.
Reporting frequency
Track PM compliance weekly and report it monthly. Weekly tracking lets you catch problems early: if compliance is trending down in the third week, you still have time to recover before month-end. Monthly reporting gives you the trend line that matters for management review.
Segmentation
Do not just report one overall number. Break PM compliance down by:
- Area or department: Which parts of the plant are executing well, and which are struggling?
- Equipment criticality: Are you hitting 95% on your A-class (critical) equipment even if B-class is at 85%? PM compliance on critical equipment should always be above 95%.
- Trade or skill type: Are electrical PMs getting done but mechanical PMs are not? This might indicate a staffing or skill imbalance.
- Reason for non-compliance: Track why PMs are missed. Equipment not available, parts not available, labor not available, deferred by management, etc. This data tells you what to fix.
Improvement Strategies
Improving PM compliance is not complicated, but it requires discipline and management support. Here are the strategies that work, in order of impact.
Strategy 1: Protect PM time in the weekly schedule
Block a specific portion of maintenance labor hours (typically 30-40%) for PM execution. This time is protected: only a true production-stopping emergency can pull a technician off a PM. A belt that "sounds funny" on a non-critical conveyor is not an emergency. A failed motor on the only running production line is.
This requires agreement between maintenance and operations leadership. Both sides must agree that PMs are not optional and that short-term production pressure does not override long-term reliability.
Strategy 2: Reduce the PM load to what is actually needed
Audit every PM task on the schedule. For each one, ask: does this task prevent a specific failure mode that matters? If the answer is no, or if nobody can explain what the PM prevents, consider eliminating or extending its interval.
Many plants carry PM tasks that were created 10 or 15 years ago for equipment that has been replaced, modified, or proven to not need that specific task. A PM schedule that was never pruned will be bloated with unnecessary work. RCM analysis provides a structured way to determine which PMs are justified by actual failure consequences.
A common finding: plants that audit their PM programs eliminate 20-30% of tasks as unnecessary, which frees up labor hours for the PMs that actually matter.
Strategy 3: Improve PM work order quality
A PM work order should tell the technician exactly what to do, what to check, what the acceptance criteria are, and what parts and tools are needed. Vague PMs like "inspect compressor" get done superficially or not at all.
Good PM work orders include:
- Step-by-step task list
- Specific measurements to take (e.g., "measure bearing vibration at points A, B, C; alert if above 4.5 mm/s")
- Photos showing what "good" and "bad" look like
- Parts list with part numbers and storeroom locations
- Estimated duration
- Safety precautions and permit requirements
Video SOPs attached to PM work orders are especially effective for complex tasks or tasks performed infrequently.
Strategy 4: Stage parts and materials in advance
For every PM that requires replacement parts (filters, belts, gaskets, lubricants), verify the parts are in stock before the PM is scheduled. Kit the parts with the work order so the technician can grab everything in one trip. Running out of a $12 filter that delays a $500 PM for two weeks makes no sense.
Strategy 5: Coordinate with operations on equipment availability
The weekly maintenance schedule should include agreements on when equipment will be available for PM work. This is a joint plan between maintenance and production. When a PM is scheduled for Tuesday at 2 PM, the machine should be released at 2 PM. Chronic "sorry, we cannot release it today" from operations is the second most common cause of low PM compliance.
Strategy 6: Review PM compliance weekly
Every Monday morning, review last week's PM performance. What was scheduled? What got done? What was missed and why? Assign follow-up actions for every missed PM. This 15-minute review creates accountability and catches problems before they compound. If the maintenance supervisor does not review compliance weekly, nobody else will care about it.
Strategy 7: Track the right PM compliance number
Do not inflate your PM compliance number by excluding categories. Some plants exclude PMs missed due to "equipment not available" or "deferred by management." These are valid reasons for a miss, but they are still misses. Your PM compliance number should reflect reality. The reasons for non-compliance go in the Pareto chart of missed-PM causes, not in the compliance calculation.
Strategy 8: Adjust PM intervals based on data
Use your CMMS data and equipment condition data to right-size PM intervals. If a monthly oil sample always comes back clean, extend the interval to quarterly and use the freed-up time for other PMs. If a quarterly belt inspection keeps finding belts that are already cracked, shorten the interval to monthly or add a condition-monitoring check.
This is where PM compliance connects to OEE. If you track which PMs, when completed on time, actually reduce breakdown frequency, you can focus your PM program on the tasks that deliver the most value.
The Connection Between PM Compliance and Equipment Reliability
The relationship between PM compliance and equipment reliability is not linear. At low compliance levels (below 60%), increasing compliance has a moderate effect on breakdowns. At high compliance levels (above 85%), the effect accelerates. Here is why:
At 60% compliance, you are catching some problems but missing others randomly. The ones you catch prevent some breakdowns. The ones you miss create an unpredictable mix of failures.
At 90% compliance, you are catching almost everything. The few PMs you miss are typically on less critical equipment (because most plants prioritize critical-equipment PMs when time is short). The compounding effect of consistent, thorough preventive maintenance starts showing up in the failure data: fewer breakdowns, shorter repair times (because equipment is in better baseline condition), and fewer secondary failures (where one component failure damages adjacent components because deterioration went unchecked).
Industry data shows the following pattern:
| PM Compliance | Typical Breakdown Rate (per 100 assets/month) | Reactive Maintenance % |
|---|---|---|
| Below 60% | 18-25 | 60-80% |
| 70-80% | 12-18 | 40-55% |
| 85-90% | 6-12 | 25-35% |
| Above 95% | 3-6 | 10-20% |
The math is simple: if you go from 70% PM compliance to 92% PM compliance, you can expect to cut your breakdown rate roughly in half. That reduction in breakdowns reduces overtime, emergency parts spending, lost production, and the constant stress of firefighting that burns out maintenance teams.
PM Compliance vs. PM Effectiveness
PM compliance measures whether you are doing the PMs. PM effectiveness measures whether those PMs are actually preventing failures. You need both.
A plant can have 95% PM compliance and still have high breakdown rates if the PM tasks themselves are wrong: inspecting the wrong things, using the wrong intervals, or missing critical failure modes entirely. This is why reviewing PM task content (not just completion rates) is essential.
Signs that your PMs are being completed but are not effective:
- High PM compliance but no improvement in breakdown frequency over 6-12 months
- Breakdowns occurring on equipment that recently had a PM (the PM did not catch the deteriorating condition)
- Technicians reporting that they complete PMs but the tasks do not match the actual equipment condition issues they see
- PMs that always take the same time regardless of what is found (suggesting they are being checked off without thorough inspection)
When you see these signs, it is time to review the PM task content, not just the completion rate. Root cause analysis on breakdowns that occurred despite recent PMs can reveal gaps in your PM program.
Where Dovient Fits
Two aspects of PM compliance are directly supported by Dovient:
- Better PM task instructions. Dovient allows you to attach video SOPs, photos, and step-by-step procedures to PM tasks. When a technician opens a PM work order, they can see exactly what to do, reducing the ambiguity that leads to superficial PM execution. Better instructions mean PMs are not just completed but completed properly.
- Capturing what technicians find during PMs. When a technician discovers an abnormality during a PM (unusual wear pattern, unexpected vibration, early-stage corrosion), that finding needs to be recorded and acted on. Dovient's knowledge base captures these observations so they can be reviewed, trended, and used to improve future PM tasks and intervals.
- Connecting PM findings to diagnostic intelligence. Over time, the observations captured during PM execution feed into Dovient's AI diagnostic engine. This means the system gets smarter about which conditions lead to failures, helping you focus PM tasks on the inspections and measurements that actually matter.
If you are working to improve PM compliance and want to see how Dovient can support better PM execution, schedule a conversation with our team.