OEE (Overall Equipment Effectiveness) is a metric that measures the percentage of planned production time that is truly productive. An OEE of 100% represents perfect production with no downtime or defects. OEE was developed in the 1960s by Japanese expert Seiichi Nakajima as part of Total Productive Maintenance (TPM) to continuously improve manufacturing processes. Measuring OEE gives manufacturers visibility into asset health and performance to reduce costs, drive efficiencies, and improve quality and capacity. Increasing OEE by just 1% can result in significant annual savings for companies.