Compute Overall Equipment Effectiveness from real shift data. Enter planned time, downtime, cycle time and output to see Availability, Performance and Quality — and the combined OEE score against the world-class 85% benchmark. Everything recalculates live in your browser.
Overall Equipment Effectiveness (OEE) is the gold-standard metric for measuring manufacturing productivity. It combines three independent factors — Availability, Performance, and Quality — into a single percentage that tells you how much of your planned production time is truly productive. An OEE of 100% means you are producing only good parts, as fast as possible, with no stop time. This calculator computes each factor and the combined OEE live from your shift data.
OEE = Availability × Performance × Quality. Each factor is a fraction between 0 and 1 (shown here as a percentage), and they multiply together.
Availability = Run Time ÷ Planned Production Time, where Run Time = Planned Production Time − Down Time. It captures all events that stop planned production for an appreciable length of time (breakdowns, changeovers, setup).
Performance = (Ideal Cycle Time × Total Count) ÷ Run Time. It captures anything that makes the process run below its maximum possible speed (minor stops, idling, reduced speed). Performance can never exceed 100% in a correct calculation — if it does, your ideal cycle time is set too slow.
Quality = Good Count ÷ Total Count. It captures produced parts that do not meet quality standards, including parts that need rework.
OEE is designed to expose the Six Big Losses, the universal causes of lost productivity in TPM (Total Productive Maintenance):
Availability losses — (1) Equipment failure / unplanned stops, (2) Setup and adjustments / changeover.
Performance losses — (3) Idling and minor stops (jams, misfeeds, cleaning), (4) Reduced speed / slow cycles below the design rate.
Quality losses — (5) Process defects (scrap and rework during steady-state production), (6) Reduced yield / startup rejects from warm-up, after a changeover, or after a stoppage.
Because the three factors are multiplied, a single weak factor drags down the whole score. A line at 90% Availability, 90% Performance, and 90% Quality is only 0.9 × 0.9 × 0.9 = 72.9% OEE.
Suppose a shift has 420 minutes of planned production time with 47 minutes of downtime, an ideal cycle time of 1.5 seconds/unit, 14,280 units produced and 14,152 good units.
Run Time = 420 − 47 = 373 min. Availability = 373 ÷ 420 = 88.8%.
Performance = (1.5 s × 14,280) ÷ (373 min × 60 s) = 21,420 ÷ 22,380 = 95.7%.
Quality = 14,152 ÷ 14,280 = 99.1%.
OEE = 0.888 × 0.957 × 0.991 = 84.2% — just shy of the world-class 85% benchmark.
OEE of 100% is perfect production. OEE of 85% is considered world-class for discrete manufacturers and is a common long-term goal. OEE of 60% is fairly typical for discrete manufacturers and indicates substantial room for improvement. OEE of 40% is not uncommon for plants just starting to track and improve performance — and is usually easy to improve through straightforward measures. Rather than chasing an absolute number, use OEE as a baseline and track the trend: which of the three factors, and which of the Six Big Losses, is costing you the most, and attack that first.
Utilization typically only measures whether equipment was running (similar to the Availability factor) and ignores speed and quality. OEE is more complete: it multiplies Availability × Performance × Quality, so it penalizes a machine that runs all shift but does so slowly or produces scrap. A machine can be 100% utilized yet have a low OEE.
No. Planned Production Time is the time the equipment is scheduled and expected to be producing. Time the plant intentionally does not schedule production (no orders, planned maintenance windows, breaks where the line is deliberately stopped) is excluded up front. Only events that stop planned running — breakdowns and changeovers — count as Down Time and reduce Availability.
Performance above 100% almost always means the Ideal Cycle Time you entered is slower than the line actually ran. The Ideal Cycle Time must be the theoretical fastest cycle the equipment can achieve (the nameplate / design rate). If you use an inflated, conservative cycle time, the math reports the line running faster than ideal, which is impossible. Use the true fastest observed or design cycle time.
Find the weakest of the three factors first. Low Availability points to breakdowns or long changeovers — apply SMED (quick changeover) and preventive maintenance. Low Performance points to minor stops and slow running — investigate jams, idling and speed losses. Low Quality points to scrap and rework — apply root-cause and mistake-proofing (poka-yoke). Because the factors multiply, fixing the lowest one yields the biggest OEE gain.
Yes, but be careful with the constraint. For a line, base Performance and Quality on the line's constraint (bottleneck) machine, and count only good units that exit the end of the line. OEE on a single non-bottleneck machine can look great while the line as a whole underperforms, so line-level OEE — sometimes called TEEP or OOE variants — should track the constraint. See the Theory of Constraints guide for how the bottleneck governs throughput.