Calculation reviewed: 4 October 2026 · Engineering Desk Tools
How to use the Maintenance KPIs: PM compliance, planned work and backlog calculator
Calculate PM compliance, planned work percentage and backlog in weeks of work. Start with measurements or documented values for the equipment and reporting period you actually want to assess. The calculator does not fill in a typical installation for you. Its blank fields help keep a demonstration value from being mistaken for your own operating data.
Choose the required options, enter the values in the labelled units and select Calculate. If a field is rejected, check its range and unit before changing it. The result is accompanied by the equation and assumptions so you can decide whether it answers your engineering question.
Inputs and measurement basis
- PM tasks scheduled in the period. Number of PM tasks that fell due in the period. The minimum is 1.
- PM tasks completed on time. Of those, the tasks finished within your allowed window.
- Planned maintenance hours. Hours spent on planned and scheduled jobs.
- Total maintenance hours. All maintenance hours, including reactive work, on the same basis. The value must be greater than zero.
- Open backlog (labour hours). Approved, ready-to-schedule work in labour hours.
- Weekly planned labour capacity (hours per week). Labour hours available for planned work each week. The value must be greater than zero.
Record the measurement source and operating condition. Retain unrounded values for verification.
Method and interpretation
Three indicators give a quick view of maintenance control. PM compliance shows how much scheduled preventive work was done on time. Planned work shows how much effort goes into planned rather than reactive jobs. Backlog in weeks shows how long the outstanding approved work would take at the current planned capacity.
PM compliance (%) = PM tasks completed on time / PM tasks scheduled × 100. Planned work (%) = planned maintenance hours / total maintenance hours × 100. Backlog (weeks) = open backlog hours / weekly planned labour capacity.
Agree the definition before comparing sites or months. On time usually means within an allowed window around the due date, and the policy for rescheduled or cancelled tasks must be written down. Use the same hours basis for planned and total hours, and the same period for tasks. Backlog normally counts approved, ready-to-schedule work and excludes emergency work. These figures are management indicators, not a measure of maintenance quality.
Worked example
This example does not populate the form. Enter your own installation data.
Calculated result: 90 % PM compliance. Track these indicators monthly and compare trends rather than a single value. Confirm that the definitions match your site procedure.
Check the arithmetic independently using the displayed equation. Retain intermediate precision and compare the final value with your equipment documentation.
Quick-reference table
These are illustrative values, not certified ratings or manufacturer data. Use the form for your own conditions.
Common mistakes
Counting late or rescheduled tasks as on time; mixing different hours bases; including emergency jobs in the backlog; comparing sites that define compliance differently; chasing the percentage instead of the quality of the work. Before relying on the output, check the decimal format, unit scale and source of each value. Recheck unusual results against the formula.
Frequently asked questions
Are the example values used automatically?
No. Inputs remain blank when the tool opens or when you clear them. The worked example and table are reading material below the calculator. Enter the actual values you want to check each time, and label saved reports so their context is not lost.
What does the result mean?
The results show how well preventive work is being completed, how much work is planned and how many weeks of backlog exist. Watch the trend and keep the definitions constant.
Can I use a zero or a negative value?
The allowed range follows the meaning of each input. A divisor needs a positive value; other fields may allow zero. Check the form labels and error message rather than forcing an invalid value. A rejected input must be corrected before a result can be shown.
Is this a final design or equipment approval?
No. Agree the definition before comparing sites or months. On time usually means within an allowed window around the due date, and the policy for rescheduled or cancelled tasks must be written down. Use the same hours basis for planned and total hours, and the same period for tasks. Backlog normally counts approved, ready-to-schedule work and excludes emergency work. These figures are management indicators, not a measure of maintenance quality. Use the calculation as support for a checked decision, and review equipment documentation and applicable requirements before changing an installation or operating setting.
How can I save or share a calculation?
Calculate first, then use Copy result or Print report. Some maintenance tools also provide a CSV summary. Reports contain your own entered data, so review them before sharing. You can share the public page URL without including plant records or confidential measurements.
How do I report an unexpected result?
Use the Contact page and include the tool URL, input values, units, expected output and the reference you used. Explain the measurement basis. Exclude confidential information.
Related tools and records
Use related calculations with consistent units, periods and equipment scope.
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