---
title: "OEE: what it is and how to calculate it | attendo"
description: "What OEE (overall equipment effectiveness) is, how to calculate it from its three factors, a worked example and the mistake of hiding the planned time."
url: "https://attendo.me/en/glossary/oee"
lang: "en"
---

# OEE: what it is, how to calculate it and when it misleads

Also known as: Overall equipment effectiveness

OEE (overall equipment effectiveness) is the share of planned production time in which a machine makes good parts at its rated speed. It combines availability, performance and quality.

How to calculate it OEE = availability × performance × quality

## The three factors

- **Availability:** run time divided by planned time. It captures breakdowns, stops and changeovers.
- **Performance:** what was produced versus what would have been produced at rated speed in that time. It captures minor stops and slow running.
- **Quality:** good parts divided by total parts. It captures scrap and rework.

## An example

A line has 8 planned hours and stops for 1 hour: 87.5% availability. In its 7 running hours it makes 3,150 parts, when rated speed would give 3,500: 90% performance. Of those, 3,087 are good: 98% quality.

OEE is 0.875 × 0.90 × 0.98, or 77%. Each factor looks acceptable on its own. Together they say almost a quarter of the planned time is lost.

## What maintenance owns

Maintenance mostly drives [availability](https://attendo.me/en/glossary/availability), plus part of performance through minor stops. Quality also depends on raw materials and the process. That is why OEE is a plant metric, not just a maintenance one.

## The usual mistake

Reporting OEE without saying which planned time it uses. Exclude scheduled stops, changeovers or shifts with no orders, and the same equipment jumps from 60% to 85% without anything changing. Before comparing two OEE figures, compare how they are calculated.

## In attendo

The KPI tab of [attendo CMMS](https://attendo.me/en/cmms) calculates OEE with its three factors, next to [MTBF](https://attendo.me/en/glossary/mtbf) and [MTTR](https://attendo.me/en/glossary/mttr), each with its target, formula and traffic light. Downtime type and duration come from each work order.

- [attendo CMMS](https://attendo.me/en/cmms)

## Where it is used in attendo

### Modules

- [Assets and inventory](https://attendo.me/en/modules/assets): Each asset with its own record, QR code, history and readings
- [Reports and dashboards](https://attendo.me/en/modules/reports-and-dashboards): Reports and dashboards for every area, with today’s data

### Industries that use these modules

- [IT services and MSPs](https://attendo.me/en/industries/it-services)
- [Hospitality, retail and multi-site](https://attendo.me/en/industries/multi-site-operations)
- [Facility maintenance and services](https://attendo.me/en/industries/facility-maintenance)
- [HVAC and refrigeration](https://attendo.me/en/industries/hvac)
- [And any other business](https://attendo.me/en/industries)

## Related terms

Maintenance

### Availability

Asset availability

Availability is the percentage of time an asset is in a condition to operate.

Maintenance

### MTBF

Mean time between failures

MTBF (mean time between failures) is the average time a piece of equipment runs properly between one breakdown and the next. It measures reliability.

Maintenance

### MTTR

Mean time to repair

MTTR (mean time to repair) is the average time it takes to bring equipment back into service after it fails. It measures responsiveness, not reliability.

[See all 53 glossary terms](https://attendo.me/en/glossary)

## Shall we look at it with your data?

We will show you how what you just read works in attendo, with your own assets, tickets and customers. If it is not a fit, we will tell you.

- With your operation, not a generic demo
- A real person from our team replies
- No cold calls afterwards

Would you rather talk first?

- Phone [+34 910 053 530](tel:+34910053530)
- Email [sales@attendo.me](mailto:sales@attendo.me)
- Monday to Thursday 9:30 AM to 6:30 PM and Friday 9:30 AM to 2:30 PM (Spain time)