What is OEE?
Overall Equipment Effectiveness (OEE) is the share of planned production time in which a line made good product at its ideal speed. It multiplies three factors, Availability, Performance and Quality, so the losses compound: a line scoring 90% on each lands at 72.9% overall. It is the standard scorecard of manufacturing.
What it is
OEE answers one question: of the time you planned to run, how much produced good product at full speed? It does so by multiplying three ratios, each a percentage of the one before it.
| Factor | Question it answers | Lost to |
|---|---|---|
| Availability | Was the line running when it should have been? | Breakdowns, changeovers, waiting for material or people. |
| Performance | While running, did it run at its ideal speed? | Interruptions, slow cycles. |
| Quality | Were the units good first time? | Scrap, rework, start-up rejects. |
OEE = Availability × Performance × Quality. Because the factors multiply, OEE is a product, not an average, and one weak factor drags the whole score down: 90% × 90% × 90% = 72.9%. Measured against all calendar time rather than planned time, the same arithmetic becomes TEEP (Total Effective Equipment Performance), which adds a Utilisation factor for the shifts you chose not to run. The full worked calculation, with every formula, is on How to calculate OEE.
Source: Augos Executive Summary report; TEEP: industry definition (Vorne, oee.com)
Availability
Availability is the share of planned production time that the line was actually running. It is lost to unplanned stops (breakdowns, faults, waiting) and to planned stops that overrun their standard (changeovers, cleaning, breaks). On many lines it is the largest of the three losses, because every unplanned stop drags a chain of human response behind it before production resumes: someone has to notice, decide, call, arrive and fix.
Performance
Performance is whether the line ran at its ideal speed during the time it was running. Two different things drag it down, and most systems blur them together. Speed loss is the line running slower than its ideal cycle. Interruptions (what standard OEE calls minor stops or micro-stops) are brief stoppages and idling, often only seconds long, too short for anyone to log by hand. Interruptions depress the speed figure, so a machine that runs fast but stutters looks identical to one that is simply slow, and the two need opposite fixes.
Augos separates them. It measures true speed, how fast the line runs when it is actually running, in real time, and reports interruptions as their own measured stop loss. Speed loss and interruptions then each show their own impact.
Stops
Stops are halting events on the line. Augos classifies them as planned stops, unplanned stops and interruptions; the duration thresholds are configured for each site. Interruptions are the short stoppages, often under about two minutes, that hide root causes when they are lumped into a single Performance number. Counted separately, they become a loss you can see, own and recover, rather than a blur inside speed.
Source: Augos Glossary; Downtime Report
Quality
Quality is the share of units that came out good first time, without rework. It is lost to scrap and rework during steady running, and to the start-up rejects made while a process stabilises after a stop, which ties Quality back to how cleanly stops are handled.
The six big losses
The six big losses are the classic map of where OEE goes, each tied to a factor. Standard OEE stops at the loss category. OEE+ adds one more column: the owner, the function that can recover the time.
| Factor | Loss | Typical cause | Owner (OEE+) |
|---|---|---|---|
| Availability | Breakdowns | Equipment fault | Technician |
| Availability | Setup and adjustment | Changeover, cleaning overrun | Planning (the scheduled time); Operator (the overrun) |
| Performance | Small stops and idling | Interruptions, material starve | Operator; Planning or External for starve |
| Performance | Reduced speed | Operator pace, or a mechanical limit | Operator, or Technician |
| Quality | Process defects | Scrap and rework in steady running | Quality; Operator for rework |
| Quality | Reduced yield | Start-up rejects after a stop | Quality |
Source: Owner table, Augos Factory method
Benchmarks
The most widely quoted OEE benchmarks come from Vorne's OEE reference: 85% is often called world class for discrete manufacturing, 60% is described as typical, and 40% is common for plants measuring for the first time. Treat them as orientation, not targets. A plant's own best shift is a better target than a textbook number, because it was achieved on that line, with that product and that crew. Across the Augos fleet, the average gap between a line's current OEE and its own Best Operator Benchmark is about 18 OEE points.
Source: benchmark tiers, Vorne, oee.com (external); fleet gap, Augos Factory method
More on what a good score looks like for your line: What is a good OEE?
Measuring OEE
Augos measures all three factors from events, not estimates. A pulse sensor counts every machine cycle without touching the PLC, and the Augos Operator Terminal captures each stop and its reason as it happens. Standard OEE is kept intact, so it reconciles to Availability × Performance × Quality, and the same data carries two things the number never did: an owner on every lost minute, and a benchmark set by your own line's best runs rather than a textbook target.
Source: Augos Factory method
Who owns the loss
Standard OEE shows the loss. OEE+ shows who owns it. Every lost minute is assigned to one of six owners: operator, technician, planning, quality, external or shared. That turns a percentage into a conversation about what to do on Monday morning, and it is the reason a plant that already measures OEE still has capacity to find. OEE+ and the Owner column →
Source: Augos Glossary
Common questions
What does OEE stand for?
Overall Equipment Effectiveness. It is a single percentage for how much of planned production time produced good product at the line's ideal speed, calculated as Availability × Performance × Quality.
What does 85% OEE mean?
That 85% of planned production time produced good product at ideal speed and 15% was lost to stops, slow running and defects. 85% is the figure most often quoted as world class for discrete manufacturing, from Vorne's OEE reference. Most plants measuring for the first time are far lower.
What does 100% OEE mean?
Perfect production: no stops, every cycle at ideal speed, every unit good. It is a theoretical ceiling, useful as the denominator of the calculation, not a target.
Is a higher OEE always better?
Usually, but not blindly. Pushing performance by overproducing stock you cannot sell is not a real gain. Read OEE alongside what the plant actually needed to make.
Why separate true speed from interruptions?
Because they have opposite fixes. A slow line needs a process or tooling change; a stuttering line needs its interruptions chased. Blended into one Performance number, you cannot tell which problem you have.
What is the difference between OEE and TEEP?
OEE is measured against planned production time. TEEP (Total Effective Equipment Performance) is measured against all calendar time, so it also counts the shifts you chose not to run as a Utilisation loss. TEEP is always equal to or lower than OEE.