OEE stands for Overall Equipment Effectiveness. The formula for calculating it is as follows:

  • OEE= Degree of availability x Degree of performance x Degree of quality.
  • OEE= Possible production time / Actual production time x Possible output / Actual output x Actual output / Flawless products

This formula was developed by the Japanese Seiichi Nakajima and helps companies to detect and eliminate losses in production. In an optimal case, a machine runs at its capacity limit and does not cause any waste. In reality, this cannot be achieved because efficiency is affected by the following losses of machinery and equipment:

  1. Equipment breakdowns
  2. Set-up and adjustment
  3. Tool changes
  4. Start-up losses
  5. Speed losses
  6. Short downtimes
  7. Scrap and rework
  8. Planned downtimes

The OEE formula shows in which areas losses occur and thus offers the possibility of eliminating them by means of optimisation approaches.