What is OEE?

Overall Equipment Effectiveness provides a way to measure the effectiveness of manufacturing operations from a single piece of equipment to an entire manufacturing plant, or several manufacturing plants in a group. In doing so, OEE provides a complete picture of where productive manufacturing time and money is being lost and uncovers the true, hidden capability of the factory. It becomes the key manufacturing decision support tool for continuous improvement programmes.

OEE - the concept

OEE measurement is made up of three underlying elements, each one expressed as a percentage and accounting for a different kind of waste in the manufacturing process:

Availability: a measure of the time the plant was actually available for production compared to the manufacturing requirements. Any losses in this area would be due to major breakdowns or extended set up time.

Performance: the rate that actual units are produced compared to the designed output. Losses in this area would be due to slow speed running, minor stoppages or adjustments.

Quality: a measure of good quality, saleable product, minus any waste. Loses for this element would be damaged rejects or products needing re-work.

oee = availability x performance x quality


Once the OEE calculation has been made, a gap analysis is undertaken between the current plant efficiency and the desired target or benchmark. The necessary investment and optimisations can be undertaken and progress monitored through the Overall Equipment Effectiveness calculation.

A 1% improvement in OEE is often a step-function improvement in losses sustained and can result in savings of thousands towards the
bottom line