Overall Equipment Effectiveness is the most widely cited metric in manufacturing analytics. It is also the most commonly misunderstood.
OEE measures how effectively a manufacturing operation uses its equipment compared to its theoretical maximum. A score of 100 percent means you are producing only good parts, as fast as possible, with no downtime.
The three components
Availability is the percentage of scheduled production time that the machine was actually running. If you schedule 8 hours and the machine was down for 2, your availability is 75 percent.
Performance is how fast the machine ran compared to its theoretical maximum speed. If a machine can produce 100 parts per hour but averaged 85, performance is 85 percent.
Quality is the ratio of good parts to total parts produced. If you produced 1000 parts and 50 were rejected, quality is 95 percent.
OEE equals Availability times Performance times Quality. At 75 percent availability, 85 percent performance, and 95 percent quality, OEE is 60.6 percent. That is where most manufacturers actually start.
Why tracking it manually does not work
OEE calculated from shift reports has two problems. It is always retrospective - you find out what happened yesterday, not what is happening now. And it relies on operators recording data accurately under production pressure, which they do not always do.
Real-time OEE requires a data connection to your production equipment, either through your SCADA system, your MES, or direct PLC communication. The moment you have live data, OEE becomes a tool for intervention, not just analysis.
If you want to implement real-time OEE tracking for your operation, reach out. We have built this for manufacturers across several different equipment and ERP environments.
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