OEE Calculator
OEE stands for Overall Equipment Effectiveness. It is a metric that measures how efficiently a production equipment, line, or facility operates based on three fundamental performance factors: time, speed, and quality. OEE is a comprehensive performance indicator that assesses the overall efficiency of a machine, production line, or facility within manufacturing processes.
It is calculated by multiplying three key performance indicators: Availability, Performance, and Quality.
At its core, OEE determines the percentage of what you could produce under optimal conditions versus what you actually produced.
OEE stands for Overall Equipment Efficiency, a standard used to measure the efficiency of your manufacturing processes.
Availability
This component measures the actual operating time of your machines as a percentage of the planned operating time. It accounts for unplanned downtimes or outages. By tracking downtime, you can identify and address frequent interruptions.
Performance
This assesses how fast your machines or production lines are operating compared to their maximum speeds, evaluating the speed of your production process. Are you operating at maximum capacity? If not, where are the bottlenecks? What are the issues and root causes?
Quality
This evaluates the ratio of quality products to the total products produced. It helps identify issues that lead to defective products (scrap) during the production process. This component focuses on the ratio of defect-free products to the total quantity produced.
OEE serves as an important criterion for manufacturers, providing insights into production inefficiencies and areas for improvement. By leveraging Retmes' accurate, logical, and real data analysis and reports, manufacturers can:
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Reduce production costs
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Decrease rework processes
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Increase production volume without investing in new equipment
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Improve product quality while enhancing efficiency
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Boost customer satisfaction
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Increase capacity utilization and accelerate delivery performance
Most importantly, our Retmes MES solution ensures that all these improvements are sustainable.
Although OEE calculation is a reliable measurement method, it is important to pay attention to these criteria and avoid significant errors in its application.
Misinterpretation of Pauses: Failure to consider pauses such as product/mold/equipment changes or short downtime, as availability losses can skew results.
Incorrect Speed Values: Using internal target speeds instead of the theoretical maximum speed can lead to incorrect performance values.
Quality Review: Neglecting quality components can lead to an overestimation of quality value than is actually the case.
Automating OEE Calculation
While manual calculations provide a basic understanding, automating the OEE calculation process brings numerous advantages.
Accuracy: Automated systems (PLC-controlled systems) ensure complete, uninterrupted, and accurate data flow.
Real-Time Analytics: Visualizes the performance of your business in real-time, enabling immediate corrective actions and providing notifications.
Efficiency: Automated systems can track even the smallest pauses that might go unnoticed in manual tracking.
Designate an OEE Officer: Assign a dedicated person or team for OEE implementation.
Automate Data Collection: Use PLC-controlled machines for more accurate data.
Visualize Data: View real-time OEE data on the shop floor for transparency.
Use our Andon Screens, exclusive to Retmes.
Review and Discuss: Implement daily review sessions to discuss production shutdowns and strategies. Plan based on Retmes' reports and analysis.
Root Cause Analysis: Drill down into issues to understand and address root causes.
Key Concepts for OEE
Before understanding OEE, it is necessary to learn some basic terms. Here are the main concepts to know about this metric:
Maximum Productive Time: The period of time that is truly productive in the production process after all losses and downtime have been subtracted.
Planned Production Time: The total targeted uptime of the equipment or system allocated for production.
Optimum Production Time: The time it takes to produce each product under ideal conditions.
Actual Working Time: The time interval during which the production process is planned and actually runs.
Total Number of Production: The number of all parts produced, including those eliminated due to quality issues.
Number of Quality Products: Number of products that meet quality control criteria and do not require rework.
Conforming Products: Products that fully comply with production standards and do not require rework.
Quality Rate: It is calculated as the percentage of produced parts that pass quality control. The formula is as follows: Quality Rate = Number of Quality Products / Total Number of Production.
Productivity: Measurement of production performance. It is calculated using the formula: Productivity = Actual Production / Planned Production.
Availability Ratio: The ratio of the time the machine is running to the total planned production time. An ideal availability means that production continues continuously during the scheduled time. Formula: Availability = Actual Running Time / Planned Production Time.