OEE components
and its 3 levers for action

Last update: October 5th, 2008
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Three components of OEE

Overall Equipment Efficiency is a synthetic rate build upon three components, featuring three "dimensions", namely:

  • Availability of machine, of equipment
  • Actual performance, in normal state
  • Quality capability

In the academic approach of TPM, OEE is built from and with different data, provides a convenient, simple and synthetic monitoring indicator. This easy monitoring helps to drive and take decisions, it's a typical manager's indicator. 

Conversely, it is possible to start from OEE and break it down in its components. The convenience of the compact OEE does not help identifying which component is the most performance limiting factor. Breaking OEE down in its three basic rates may be necessary for understanding, analysing and choosing the best action leverage for improvement.

Three levers for action

On what to focus for improving OEE?

OEE value shows a global performance rate, to know what to do to improve it, where to focus attention, it is necessary to identify which dimension limits most the performance;

  • Is it Quality?
  • Machine usable time to few?
  • its intrinsic performances (Yield, speed, takt...)?

When starting TPM, it is common that all three dimensions limit significantly Overall Efficiency. In such a case, trying to solve all problems at once is non sense, as available resources (including time!) are always limited. Therefore, focusing on most limiting factor is necessary.

Remember OEE is a ratio made of three intermediate rates;

  • Resource activation rate
  • Performance rate
  • Quality rate

These focused rates give figures about each contributing dimension, how they nag on or limit OEE.

A first glance at these rates gives hints about which dimension is accounting for most of OEE limitation. Then it must be inquired why, by breaking down the components of the "gilty" rate.

See examples

Zones for action

The "zones" giving negative effects on OEE can either be:

  • In close machine or equipment vicinity
  • Located at interfaces between two or more machines linked together
  • Located out of perimeter, like for example at supplier's or clients

According to troubleshooters location, it won't be the same person to take action. In TPM spirit, taking care of machines is operators job. Problems with interfaces are line manager or workshop manager's job. More widespread problems related to process can be adressed by operators with their supervisor(s) and eventually support of the manager in charge of the whole. External problems, limiting process or one of sub processes performance, must be adressed by concerned stakeholders. Feedback and explanations about consequences and countermeasures have to remain at manager's level.



OEE is a synthetic and composite indicator.

It strength is its weakness as well. to choose the right leverage, analyzing its components is mandatory.

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Effectiveness vs efficiency

Effectiveness = reach the objective.

Efficiency = reach the objective with savings on means or achieve more with same means.

Efficience =

Effectiveness + Savings




OEE is always less than the least of its component rates.







Process: chain of posts, machines, equipments... linked together to produce an expected result.







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