Maintenance metrics and KPIs
The maintenance metrics worth tracking, how each is calculated and what the record must hold, and how to choose the few your team can act on.
Track a metric only when someone on the team can change it and everyone calculates it the same way. Choose the few your team can act on, and calculate each one from your own records.
Choose the few metrics your team can act on
Have the owners of each process take part in choosing the metrics, after the team sets the goals they measure. Set goals the team can reach, and weigh the cost of getting the data against what the figure adds. Choose metrics the people using them understand and can influence, and tie them to the business objectives.
Keep the data behind each figure accurate
Keep the data accurate before you read any figure from it. Bad data is worse than no data, and the Records needed column in the table below is what makes a figure checkable.
Use several measures, so a gain in one shows against the rest
Use several measures together, so that a gain in one shows against the others. One area can push its own number at the cost of the whole.
Calculate each figure from the record it needs
Calculate each figure with the formula in its row. The last column lists the records your system needs to calculate it.
| Figure | Calculation | Records needed |
|---|---|---|
| Availability | Hours each unit is available to run at capacity ÷ total hours in the period | Start and end of each outage, and the period’s total hours |
| MTBF | Total operating time ÷ number of failures. Its reciprocal is the failure rate | Each failure, with the operating hours since the previous one, from CMMS history |
| MTTR | Total time to restoration ÷ number of failures restored | For each failure: the failure or detection time, and the time the asset returned to service |
| PM completion | PM actions completed ÷ PM actions scheduled | Due date and completion date for each PM, and the on-time tolerance set in writing |
| Schedule compliance | Labor hours worked on scheduled jobs ÷ labor hours scheduled | Scheduled and actual hours for each job |
| Overdue PM work orders | Count at month end, trended over time | Due date and status of each open PM |
| Emergency work | Hours on emergency jobs ÷ total hours worked | Job type on each work order |
| Maintenance cost per asset | Labor hours at the labor rate, plus parts and contracted work charged to the asset | Hours, rate, and parts used on each work order |
Start MTTR at the failure, not at the work order
Start each failure’s time at the failure, or at its detection when the moment of failure cannot be known, and stop it when the asset is back in service. IEC 60050-192 is the standard for this measure, and it marks “mean time to repair” as deprecated. It includes waiting for people, parts, approvals, and access, as well as the hands-on work. Do not enter labor hours as restoration hours.
Read MTBF asset by asset
Read MTBF asset by asset, from the asset’s own history in the CMMS, with operator logs, parts usage, and contractor records as other sources. For work orders as a whole, use schedule compliance. In FixAhead, the MTBF/MTTR report shows both figures for each asset, and the MTBF and MTTR post walks through reading it.
Measure planning with schedule compliance
Measure the planner’s work with schedule compliance: labor hours worked on scheduled jobs, against labor hours scheduled. Wrench time is the other planning figure, and a 2022 Plant Services article argues that it can be a terrible metric and is probably best left unmeasured.
Agree each definition in writing before you compare
Agree each definition in writing before you compare sites or months. Two sites can report different figures for the same month because they count different things.
- Reactive work. One definition counts work that interrupts the weekly schedule, as a share of maintenance labor hours. Another counts hours on emergency jobs. The two can differ for the same month.
- PM completion. Completed PM actions against scheduled ones sets no tolerance for how late a PM may be. Set the on-time tolerance in writing before you compare sites or months.
Count planned and reactive work the same way each month, and track the planned share over time, as The cost of PMs vs unexpected failures sets out.
Start with one project a small team can finish
Start with one project that can finish in six months to a year, on equipment with a visible history of trouble. Keep accurate records, so you can compare before and after.
Questions to ask a vendor
Ask each vendor these questions before you sign.
- How does the system calculate each figure, and can I see the formula?
- Does MTTR run from the failure or its detection, or only from the work order?
- Can PM compliance be measured against an on-time tolerance I set for each schedule?
- Can I export the raw records behind every report?
Uptime and downtime per asset
Check each asset’s uptime and downtime in FixAhead’s asset utilization report, which sorts the assets by downtime over a date range.
FixAhead has eleven built-in reports, among them MTBF, MTTR, and PM compliance. Each exports to PDF, Excel, or CSV. Calculate the figures with the MTBF calculator and the MTTR calculator. For MTBF worked through on a pump, read How to Calculate MTBF and MTTR for Your Equipment.
Read maintenance cost in FixAhead
1. Open Overview on Reports & Analytics
Overview shows Maintenance Cost beside Total Assets, Active Work Orders and Avg Response Time. Below the cards, How this cost is calculated splits the cost into Labour and Parts, with the hours worked and the completed or closed work orders behind it.
Set up PM completion first
Set up PM completion first. Write the on-time tolerance down, and record the due date and completion date of each PM, as the table above lists. Add the other figures once PM completion calculates from your records.
Read PM compliance in FixAhead
The PM Compliance report rates each asset’s preventive maintenance.
1. Open PM Compliance under Maintenance
On Reports & Analytics, choose the Maintenance tab, then PM Compliance. Compliance Status lists the ratings Excellent (90%+), Good (75-89%) and Poor (<75%).
2. Read each asset’s compliance
Each row gives an asset’s Scheduled and Completed PM work, its Overdue count, and its Compliance % with a Status.
