Key takeaways
Short answer: Theoretical and actual cycle time are the ideal and the real time to make a unit. Theoretical cycle time (also called ideal cycle time) is the minimum time to produce one unit when the equipment runs at its full rated speed with no losses — the best the machine can do. Actual cycle time is the real average time per unit once slow running, micro-stops, and inefficiencies are included. Actual is always longer than theoretical, and the gap between them is pure speed loss — which is essentially what the performance factor of OEE measures. For the performance factor itself, see OEE for manufacturing.
Theoretical cycle time — also called ideal or design cycle time — is the minimum time required to produce one unit when the equipment runs at its full rated speed with no losses of any kind. It is the best the machine can possibly do: the time per unit you would achieve if the equipment ran continuously at its nameplate rate, with no slow running, no micro-stops, no inefficiency. Theoretical cycle time comes from the equipment's design specification — the rate the manufacturer rates it for — and it represents the performance ceiling. It is the benchmark against which real performance is measured, but it is not what you actually achieve in practice, because real production always includes some speed loss. Theoretical cycle time is the ideal reference point: the fastest the machine can produce a unit when everything is perfect, used as the standard that actual performance is compared against.
Actual cycle time is the real average time it takes to produce one unit in practice — the total running time divided by the units produced, including all the speed-related losses that slow real production below the ideal. Actual cycle time captures what theoretical cycle time excludes: running below rated speed (a machine dialed back, or unable to hit nameplate), minor stops and micro-stops (brief pauses, jams, and idling that do not count as full downtime but add time per unit), and general inefficiency. Because it includes these losses, actual cycle time is always longer than theoretical — every unit takes a bit more time than the ideal. Actual cycle time is the honest measure of how fast the line really runs when it is running, as opposed to how fast it could run. The difference between actual and theoretical is exactly the speed loss the line is suffering.
The gap between theoretical and actual cycle time is pure performance loss — the speed the line is leaving on the table while it is running. This is a distinct kind of loss from downtime: downtime is time the machine is stopped, but the theoretical-to-actual gap is the slowness while the machine is running — it is up, but producing each unit more slowly than it could. The two sources of this gap are reduced speed (running below rated rate) and minor stops (the brief, frequent pauses that inflate the average time per unit without registering as full stoppages). These are easy to miss precisely because the machine looks like it is running — the loss hides in a slightly-slow cycle rather than an obvious stop. Quantifying the gap between actual and theoretical cycle time is what drags this hidden speed loss into the light and makes it addressable.
A machine has a theoretical cycle time of 30 seconds per unit — its rated speed, the fastest it can produce. Over a shift, it ran for 6 hours and produced 600 units. Its actual cycle time is 6 hours (21,600 seconds) ÷ 600 units = 36 seconds per unit. So while running, the machine took 36 seconds per unit against an ideal of 30 — a speed loss of 6 seconds per unit, or about 17% slower than it could be. At the ideal 30-second cycle, those 6 hours of running would have yielded 720 units, not 600 — the 120-unit shortfall is pure performance loss, suffered while the machine was up and apparently working. Note this is separate from any downtime (the 6 hours is running time only); it is the slowness within the running time. The gap from 30 to 36 seconds, multiplied across every unit, is exactly the performance loss the line should attack.
The relationship between theoretical and actual cycle time is essentially the performance factor of OEE. The performance factor is the ratio of theoretical (ideal) cycle time to actual cycle time — or equivalently, actual output divided by the output the running time should have produced at the ideal rate. In the worked example, performance is 30 ÷ 36 ≈ 83%, or 600 ÷ 720 ≈ 83% — the machine ran at about 83% of its rated speed while it was running. This is why theoretical and actual cycle time matter so much: their ratio is one of the three factors of OEE, capturing the speed loss that availability (downtime) and quality (defects) miss. A machine can be available a lot and produce good parts, yet still lose heavily on performance because its actual cycle time exceeds the theoretical — and only by comparing the two do you see it.
Theoretical and actual cycle time are the direct inputs to the performance factor of OEE — performance is essentially theoretical cycle time divided by actual cycle time. This makes the gap between them one of the three things OEE measures, alongside availability (the downtime gap) and quality (the defect gap). The speed loss it captures — reduced speed and minor stops — corresponds to two of the six big losses, and it is often the most overlooked, because it hides in a running machine rather than an obvious stoppage. Tracking actual against theoretical cycle time is what surfaces this loss; the performance factor is precisely the number that quantifies it. A line with strong availability and quality can still have mediocre OEE entirely because of the cycle-time gap.
Fabrico measures actual cycle time against the theoretical ideal in real time, computing the performance factor and exposing the speed loss that hides in a running machine. By capturing both the reduced-speed and minor-stop components of the theoretical-to-actual gap, it shows exactly how much output is lost to slowness while the line is up — the performance loss that a downtime-only view completely misses. Seeing the cycle-time gap quantified is what makes this hidden loss addressable. Book a demo to see your real cycle time against the ideal.
Theoretical (ideal) cycle time is the minimum time to produce one unit at full rated speed with no losses. Actual cycle time is the real average time per unit, including slow running and minor stops. Actual is always longer than theoretical, and the gap is the speed loss.
Because real production includes speed-related losses the ideal excludes — running below rated speed, and minor stops or micro-stops that briefly pause the line without counting as full downtime. These inflate the average time per unit above the theoretical minimum.
The performance factor of OEE is essentially the ratio of theoretical to actual cycle time — or actual output divided by the output the running time should have produced at the ideal rate. The cycle-time gap is exactly the speed loss the performance factor measures.
Two things: reduced speed (the machine running below its rated rate) and minor stops (brief, frequent pauses, jams, and idling). Both slow the real average time per unit below the ideal, and both hide in a machine that looks like it is running.
Use the equipment's genuine rated or design speed — the fastest it can truly produce a unit. Do not set it to what you currently achieve (that hides the loss), and do not use an unrealistic nameplate the machine can never hit (that makes performance look artificially bad).
Anmeldung
Blog
