# OEE

## OEE

OEE (Overall Equipment Effectiveness) is a KPI expressed in percentage points that indicates the degree of production efficiency of a machine/plant.

This KPI is considered the product of three different indicators:

```
OEE = AV * PERF * QUAL
```

An OEE of 100% indicates that the machine/plant produces only compliant parts, without any fault and at the fastest possible speed.

<figure><img src="https://content.gitbook.com/content/pAbYPeH0IeVsC8b0gI87/blobs/Ro4o9NwXH6c4SuID3xQS/oee-calculation.png" alt=""><figcaption></figcaption></figure>

## Global OEE

The global OEE is a varation of the OEE that use the global availability instead of the standard availability

```
GLOBAL OEE = GLOBAL AV * PERF * QUAL
```

A gloabl OEE of 100% indicates that the machine/plant produces only compliant parts, for all the planned time and at the fastest possible speed.

## Availability

The ratio of the time the machine was actually engaged in machining the part, net of all stops due to breakdowns.

The formula is:

```
AVAILABILITY = UPTIME / (UPTIME + DOWNTIME)
```

An availability of 100% means that the machine/plant produces without any fault.

## Global Availability

The ratio of the time the machine was actually engaged in machining the part, net of all stops due to breakdowns, setups, scheduled maintenance, and the potential time during which the machine could work.

The formula is:

```
AVAILABILITY = UPTIME / PLANNED TIME
```

A 100% rate means that the machine/plant produces for as long as it was planned, without any interruption.

## **Performance**

Percentage of parts produced compared to theoretical potential when the plant is active:

```
PERF = (N.PRODUCED PIECES) / (N.PIECES THEORETICALLY PRODUCED) 
```

A rate of 100% means that the machine/plant always produces at maximum speed.

## Quality

Percentage of conforming parts to total parts produced:

```
QUALITY = (N. CONFORMED PIECES) / (N. PRODUCED PIECES)
```

A percentage of 100% means that the machine/plant produces only good parts.

{% hint style="warning" %}
The third component, quality, is not always present in the OEE calculation; it depends on the presence or absence of quality detection systems.
{% endhint %}
