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Industrial automation · manufacturing · OT — updated 2026-09-25

OEE calculator

Availability × performance × quality from your shift numbers, with the six big losses mapped to each factor.

Planned time excludes scheduled breaks and planned maintenance only.

OEE

77.6 % = 90.63 % × 89.66 % × 95.51 %

FactorValueLosses behind it
Availability90.63 %Breakdowns · setup & adjustments (45 min lost)
Performance89.66 %Idling & minor stops · reduced speed (90 units below theoretical 870)
Quality95.51 %Defects & rework · startup rejects (35 units lost)

Overall equipment effectiveness compresses a shift into one number: OEE = availability × performance × quality. Availability is run time over planned production time (downtime losses). Performance is actual output over theoretical output at ideal rate (speed losses). Quality is good units over total units (defect losses).

Enter honest numbers

The most gamed input is planned production time: exclude only scheduled breaks and planned maintenance — not "we had no orders" and not changeovers you chose not to count. Ideal rate should be the demonstrated best sustained rate (or nameplate), not a wish. Enter total units started and good units; scrap plus rework is the quality loss.

Read the factors, not just the headline

An OEE of 65% can mean very different things: 90% × 95% × 76% is a quality problem, while 72% × 95% × 95% is a downtime problem. Fix the lowest factor first — that is where the six-big-losses mapping below the result points you: breakdowns and changeovers hit availability, minor stops and reduced speed hit performance, defects and startup rejects hit quality.

World-class OEE (85%: 90% × 95% × 99.9%) is a benchmark, not a target for every line. Trend your own line against itself before comparing across plants.

See also

Cite this page: OEE calculator, Shopfloor. https://shopfloor.space/tools/oee-calculator/

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