Total effective equipment performance: the score that counts every hour you own

Your OEE score looks respectable. The machine runs well when it runs, quality is solid, the speed is close to design, and the production team feels good about the asset. Then the finance director looks at the same machine and sees something completely different. It was bought to run three shifts a day. Most weeks it runs one.

Both views are correct, and that is exactly the trouble. OEE only scores the hours you chose to schedule. It has nothing to say about the hours you left empty, and for an expensive asset those empty hours are often where the real money is hiding.

What it actually measures

Total effective equipment performance, or TEEP, takes everything OEE measures and adds one more question on top: of all the calendar time there is, every hour of every day, how much did you schedule the asset to run in the first place?

It multiplies four factors instead of three:

• Utilisation. What share of all calendar hours did you actually schedule?
• Availability. When scheduled, was it running?
• Performance. When running, was it at full speed?
• Quality. Of what it made, how much was good first time?

The last three are simply OEE, so you can read TEEP as your utilisation multiplied by your OEE. Where OEE measures the asset against the hours you asked of it, TEEP measures it against every hour on the clock, the full twenty-four hours a day, every day of the year. It is the right lens for the biggest questions a business asks of its assets: do we have enough capacity, should we add a shift, do we buy the next machine or load the one we have?

How to work it out

TEEP = Utilisation × Availability × Performance × Quality

Take a single asset over one day.

TEEP = 66.67% × 76.63% × 59.88% × 92.00% = 28.14%

The asset spent a third of its day idle by design, so before you even glance at speed or quality, more than a third of its calendar capacity was never scheduled at all. That is not a maintenance failure. It is a capacity planning conversation waiting to happen.

Why a great OEE can hide a poor TEEP

This is the gap TEEP exists to expose, and it can be startling. A six-station assembly machine can post a genuinely world-class OEE of 88 per cent and still come out at a TEEP of just 49, purely because it sits idle for nearly half of all the hours in the year. On the shift it works, it is excellent; measured against the calendar it owns, it is barely scraping half.

The same trick lurks inside any availability figure. Take a press that looks world-class against its scheduled hours, then re-base it against every hour on the calendar instead, and the proud number slides toward the low sixties. Neither version is wrong; they answer different questions. The danger is quoting the flattering one and forgetting the other exists. TEEP is the discipline of always knowing the denominator you chose.

What good looks like

There is no universal target, because the right number depends entirely on how much of the clock your business actually needs to fill. As a rough guide, utilisation in a typical plant runs somewhere around 60 to 80 per cent of the calendar, while world-class operations push it into the 85 to 95 range, but a plant serving a thin or seasonal market will sit lower for perfectly good reasons. The more useful questions are whether your TEEP is trending upward, and whether the idle time buried inside it is there by deliberate choice or simply by default.

One rule always holds: TEEP can never be higher than OEE. If it comes out higher, something has been calculated wrongly.

What it is good for, and where it can mislead you

TEEP earns its keep at the capital table. A low TEEP sitting next to a high OEE is the clearest possible signal not to buy more capacity but to load what you already own; the cheapest machine you will ever find is the one already on your floor, standing idle. It also lets you put a price on that idleness: cost the empty hours in money and a turnaround spare or a scheduling fix that buys some of them back suddenly looks like the bargain it is.

A few cautions:

• Use it at the level of a single asset, not rolled up across a plant. Averaged over a site it becomes too blunt to act on.
• A low TEEP is not automatically a problem. If the asset is idle because demand genuinely does not need it, the metric is doing its job by revealing latent capacity, not calling for more maintenance.
• Performance cannot exceed 100 per cent. If it does, the best-rate reference was set too low; correct the reference, not the score.
• Most of what drives TEEP, demand, scheduling, material supply, lives well outside the maintenance team's control. It is a business lens, not a verdict on your technicians.

OEE asks whether you ran the asset well. TEEP asks the harder question sitting underneath it: whether you ran it at all. For a business weighing up whether to buy the next machine, that is often the only question that matters, because the cheapest capacity you will ever find is the capacity already sitting idle in the assets you own.