Maintenance KPIs Explained: MTBF, MTTR and More
MTBF (mean time between failures) is the average operating time between one failure and the next, calculated as total operating time divided by the number of failures. MTTR (mean time to repair) is the average time needed to restore equipment after a failure, calculated as total repair time divided by the number of repairs. Higher MTBF and lower MTTR mean more available equipment.
Core maintenance KPIs and formulas
| KPI | What it measures | Basic formula |
|---|---|---|
| MTBF | Reliability of an asset | Total operating time ÷ number of failures |
| MTTR | Speed of repair | Total repair time ÷ number of repairs |
| Availability (uptime %) | Share of time the asset can operate | MTBF ÷ (MTBF + MTTR) × 100 |
| Downtime (max, min, average) | How long equipment is out of operation | Sum or average of out-of-service periods |
| PM compliance | Discipline of the preventive program | PM jobs completed on time ÷ PM jobs due × 100 |
| Maintenance vs equipment cost | Whether an asset is still worth maintaining | Maintenance cost ÷ equipment cost × 100 |
| Failures per equipment | Problem assets | Count of failures per asset over a period |
| Manpower load | Workload balance | Maintenance tasks or hours per technician |
Worked example
A pump runs 1,000 hours in a quarter and fails 4 times. Its MTBF is 1,000 ÷ 4 = 250 hours. If the four repairs took 10 hours in total, MTTR is 10 ÷ 4 = 2.5 hours, and availability is 250 ÷ (250 + 2.5) ≈ 99.0%.
How to use these KPIs
- Rank assets by failures and downtime to decide where preventive maintenance should focus.
- Watch MTTR to find delays in spare parts, skills or approvals.
- Compare maintenance cost with equipment cost to support repair-or-replace decisions.
- Benchmark sites, teams and service providers using the same definitions.
Maintenance KPIs in Steady OMS
Steady OMS dashboards include maximum, minimum and average downtime, the PM performance meter, the maintenance event log, MTBF, manpower load, maintenance versus equipment cost, average time between failures, average time to repair and uptime %, and downtime versus throughput. The homepage lists more than 75 OMS KPIs in total.
Related reading: Preventive vs corrective maintenance · What is an OMS?
Frequently asked questions
What is a good MTBF?
There is no universal value. MTBF depends on the asset type, operating conditions and how failures are defined, so it is most useful for tracking the same asset or asset class over time.
What is the difference between MTTR and downtime?
Downtime is the total time equipment is unavailable. MTTR is the average repair time per failure and is one of the factors that make up downtime.
Talk to Steady Solutions
Tell us about your sites, assets and processes, and our team will show you how Steady OMS, ERP or HIS fits your organization. You can also contact us directly or call +966 55 337 0220.