OEE (overall equipment effectiveness) is a measure of how effectively a machine or line is used during planned production time. It multiplies three rates: availability, performance, and quality.
OEE comes from total productive maintenance (TPM). It breaks losses into three rates. Availability captures downtime from failures, setups, and adjustments. Performance captures running slower than the ideal rate and minor stoppages. Quality captures scrap and rework. Together these cover the classic "six big losses."
Example: 90% availability × 95% performance × 99% quality gives about 84.6% OEE. The data typically comes from machine states (run, stop, fault), part counters, the ideal cycle time, and reject counts, often collected by an MES or line monitoring system. To run the numbers for your own line, use the OEE calculator.
OEE is easy to game and easy to misread. Results depend on what counts as planned time and which ideal cycle time is used, so numbers from two plants are rarely comparable. A single OEE figure hides which loss dominates; the three components matter more than the product. An often-quoted benchmark calls 85% "world class," but it is a rule of thumb, not a standard.
The three OEE rates
| Rate | Losses it captures |
|---|---|
| Availability | Downtime from failures, setups and adjustments |
| Performance | Running slower than the ideal rate, and minor stoppages |
| Quality | Scrap and rework |
Questions about OEE
How is OEE calculated?
Multiply the three rates: availability, performance and quality. For example, 90% availability times 95% performance times 99% quality gives about 84.6% OEE.
Is 85% OEE world class?
An often-quoted benchmark says so, but it is a rule of thumb, not a standard. Results depend on what counts as planned time and which ideal cycle time is used, so numbers from two plants are rarely comparable.
What data do you need to measure OEE?
Machine states (run, stop, fault), part counters, the ideal cycle time and reject counts. This data is often collected by an MES or a line monitoring system.
OEE in real plants
- Tuffaloy and MachineMetrics: Resistance welding parts maker Tuffaloy runs MachineMetrics on 14 connected lathes in Greer, South Carolina, linked to its Epicor Kinetic ERP for cycle times, downtime and part counts.
- Lonza and Seeq: Lonza developed an OEE solution in Seeq with real-time monitoring at its Portsmouth, New Hampshire facility and is expanding it globally.
- DNP and MachineMetrics: Industrial printing manufacturer DNP uses MachineMetrics machine data with MaintainX work orders at its North Carolina operation for live downtime tracking and usage-based maintenance.
- Hamilton Company and MachineMetrics: Hamilton Company connected 86 machines in its Nevada machine shop to MachineMetrics for real-time production data, utilization reports and cycle time tracking.
- Wall Colmonoy and MachineMetrics: Wall Colmonoy uses MachineMetrics for real-time production monitoring of EDM, CNC wire cutting and turning machines at its facility in Pontardawe, Wales.
Vendors linked to OEE
MachineMetrics (6) · Litmus (1) · Seeq (1) · Siemens (1) · Tulip
OEE in the digest
Related terms
MES (manufacturing execution system)
An MES (manufacturing execution system) is software that manages and records production on the shop floor.
Statistical process control (SPC)
Statistical process control (SPC) is the use of statistical methods, mainly control charts, to monitor a production process and detect when its variation goes beyond what its normal, stable behavior would produce.
Root cause analysis
Root cause analysis (RCA) is a structured method for finding the underlying cause of a failure or defect, so the corrective action prevents recurrence instead of only treating the symptom.
Lights-out manufacturing
Lights-out manufacturing is production that runs fully automated without people on site, so lights, and sometimes heating, can be switched off.