OEE Calculator

What is OEE?

OEE (Overall Equipment Effectiveness) is the gold standard metric for measuring manufacturing productivity. It identifies the percentage of planned production time that is truly productive. An OEE score of 100% means you are manufacturing only good parts, as fast as possible, with no downtime.

OEE is calculated as the product of three factors:

OEE = Availability × Performance × Quality

Each factor captures a different category of productivity loss, giving manufacturers a clear framework to identify and address the root causes of inefficiency.

How to Calculate OEE

Follow these three steps to calculate OEE from your production data:

• Step 1 - Availability: Measures unplanned and planned stops.
  Availability = Run Time ÷ Planned Production Time
  For example, if you planned 480 minutes of production and the machine ran for 432 minutes, Availability = 432 ÷ 480 = 90%.
• Step 2 - Performance: Measures slow cycles and small stops.
  Performance = (Ideal Cycle Time × Total Units) ÷ Run Time
  If the ideal cycle time is 30 seconds (0.5 min), you produced 700 units, and run time was 432 minutes, Performance = (0.5 × 700) ÷ 432 = 81.02%.
• Step 3 - Quality: Measures defects and rework.
  Quality = Good Units ÷ Total Units
  If you produced 700 units and 693 were good, Quality = 693 ÷ 700 = 99%.

Final OEE: Multiply all three factors together. For the example above: OEE = 0.90 × 0.8102 × 0.99 = 72.19%.

OEE Benchmarks

Use the table below to understand where your process stands relative to industry benchmarks:

The Six Big Losses

OEE is designed to highlight the "Six Big Losses" that reduce equipment effectiveness. Understanding which losses affect which OEE component helps you prioritize improvement efforts:

• Equipment Failure (Availability) – Unplanned breakdowns causing significant downtime. Address with preventive maintenance and reliability analysis.
• Setup and Adjustments (Availability) – Changeovers, material shortages, and startup time. Reduce with SMED (Single-Minute Exchange of Die) techniques.
• Idling and Minor Stops (Performance) – Brief stoppages caused by jams, misfeeds, or sensor issues. Often underestimated but highly cumulative.
• Reduced Speed (Performance) – Running equipment below ideal cycle time due to wear, operator caution, or suboptimal settings.
• Process Defects (Quality) – Parts produced that do not meet specifications during steady-state production. Reduce with SPC and root cause analysis.
• Startup Rejects (Quality) – Defective parts produced from startup until the process stabilizes. Minimize by optimizing startup procedures.

Why Track OEE?

OEE provides a single, unified metric that captures the full picture of manufacturing efficiency. By tracking OEE over time, manufacturers can identify trends, measure the impact of improvement initiatives, and benchmark performance across lines, shifts, and plants. It is a cornerstone of Total Productive Maintenance (TPM) and lean manufacturing programs, enabling data-driven decisions that reduce waste, increase throughput, and improve product quality without requiring additional capital investment.