A measure of how effectively equipment is being used.
OEE is calculated by multiplying the machine availability rate by its performance rate and by its quality rate (OEE=ARxPRxQR). Availability rate measures downtime as a percentage of scheduled time. Performance rate measures the percent decrease from design speed the machine can be operated. Quality rate measures the percent of total parts that are scrapped or reworked.
OEE should not be used as a primary metric to be improved as a goal, as it can drive unwanted behaviors by reacting positively to doing fewer changeovers. Additionally, OEE should only be watched on critical machines; little money should be spent on machines that already easily meet throughput or quality needs.