OEE
Availability times performance times quality. All three, or the product calls it an A×Q score instead and says which component is missing.
Formula
In practice
Three factors, or a score that says it is not OEE. Availability, performance and quality multiplied together is the figure; where a record exists but no ideal cycle time or run time does, the product reports availability × quality, marks it as an A×Q score and names the component it is missing. Where a process has no equipment record at all — as office and service processes do not — nothing is produced and the caller is told why. A process is not at 0% OEE merely because nobody has agreed its ideal cycle.
Availability may be measured or stated, and the two are not equal claims. Planned time against run time is preferred wherever both exist, because it feeds the performance factor and its difference is a quantity of lost time somebody can argue with. A plant that holds uptime only as a percentage — the common case, and the form Learning to See publishes it in — may state it directly; a stated ratio carries no period, so it is read against that process's own working day. A performance factor above 1 means the recorded ideal cycle time is understated: it is capped at 1 and reported, rather than quietly clamped into something plausible.
How this is calculated
availability = run time / planned production time (or the stated uptime)
performance = (ideal cycle time × total count) / run time
quality = final good / total
OEE = availability × performance × quality
A×Q score = availability × quality (performance unknown)
Three factors, or a score that says it is not OEE. Where a process has no
equipment record — as office and service processes do not — nothing is produced
and the caller is told why. Where the record exists but no ideal cycle time or
run time does, availability × quality is reported with isTrueOee: false and
must be labelled as an A×Q score. The predecessor reported that product under
the name OEE; the objection was always to the name, not to the number, and a
process is not at 0% OEE merely because nobody has agreed its ideal cycle.
Convention: availability may be measured or stated, and the two are not
equal claims. Planned time against run time is preferred wherever both exist:
it feeds the performance factor and its difference is a quantity of lost time
somebody can argue with. A plant that holds uptime only as a percentage — the
common case, and the form Learning to See itself publishes it in — may state
it directly. A stated ratio carries no period, so it is read against that
process's own working day, and the changeover correction below applies to it
unchanged. availabilityOf resolves the two in one place so that capacity and
the OEE panel cannot disagree about which was used.
A performance factor above 1 means the recorded ideal cycle time is understated. It is capped at 1 and reported, rather than clamped into something that looks plausible.
Common questions
Why will the tool not show me an OEE figure?
Because one of the three factors has no measurement behind it. Multiplying the number you have by two you assumed produces a confident figure with nothing under it. You get an A×Q score instead, labelled as such, with the missing component named — see the benchmark, where declining to answer is part of what is verified.
I only have an uptime percentage. Can I use it?
Yes. A bare percentage is accepted as a stated availability and read against that process's own working day, with the changeover correction applied unchanged. It is recorded as stated rather than measured, so a reader can see which kind of claim the figure rests on.
This definition is the one the product itself shows, read from its interface catalogue at build time.