Where is your OEE actually going?
Every point of OEE you lose falls into one of the Six Big Losses: two that stop the line, two that slow it, two that scrap what it makes. Enter the minutes each one cost this run and watch your planned time flow down the waterfall to what was truly productive, with the availability, performance and quality split alongside. Numbers update as you type.
Your losses this run
Enter the minutes lost to each loss over one planned run or shift. Reduced speed and rejects go in as the equivalent minutes of lost output (units missed times ideal cycle time).
Availability losses the line is stopped
Performance losses the line runs, but under rate
Quality losses output you cannot sell
Where your time goes
Your losses appear here, ranked biggest first.
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You can only cut the losses you can see.
Most of this chart is an estimate until something at the line is actually counting. The free OEE Tracker logs every stop and slow run as it happens, so the six losses stop being a guess and the biggest one becomes obvious.
Open the free OEE TrackerThe two losses your logs will never show you.
Small stops and slow cycles do not raise a ticket, so they stay invisible on any manual or CMMS-based record. Fabrico records every micro-stop and slow cycle from the machine and, where cameras are fitted, puts the stop on video with a suggested cause, then links that PLC-read signal to a work order opened from the stop. The performance losses above stop being a mystery and start getting fixed.
Book a Fabrico demo See how Fabrico tracks OEEThe Six Big Losses, and why two of them hide
The Six Big Losses are the standard way to account for every minute that pulls OEE below a perfect 100 percent. They sort into the three factors of OEE. Breakdowns and setup and adjustments are availability losses: the line is stopped and everyone can see it. Small stops and reduced speed are performance losses: the line is running, just not at rate. Startup rejects and production rejects are quality losses: the line made output you cannot sell. The two availability losses are visible because a stopped line gets noticed. The two performance losses are the dangerous ones, because a line that quietly runs under rate looks fine from across the floor and never generates a record.
The math
Start with planned production time. Subtract the availability losses to get operating time, and Availability is operating time divided by planned time. Subtract the performance losses from operating time to get net run time, and Performance is net run time divided by operating time. Subtract the quality losses to get fully productive time, and Quality is fully productive time divided by net run time. OEE is Availability times Performance times Quality, which is the same as fully productive time divided by planned production time. Every loss you enter above is one step down that waterfall.
Worked example (illustrative numbers)
One 480-minute shift. Breakdowns take 30 minutes and setup and adjustments 25, so operating time is 425 minutes and Availability is 425 / 480 = 88.5%. Small stops cost 20 minutes and reduced speed the equivalent of 25, so net run time is 380 minutes and Performance is 380 / 425 = 89.4%. Startup rejects take the equivalent of 5 minutes and production rejects 10, so fully productive time is 365 minutes and Quality is 365 / 380 = 96.1%. OEE is 365 / 480 = 76.0%.
Look at where the 115 lost minutes went: the two hidden losses (small stops and reduced speed) add up to 45 minutes, more than the 30 minutes of breakdowns everyone talked about. That pattern is common, and it is why the performance losses deserve a measurement before anyone argues about them. The numbers here are an example; enter your own above.
How do I put reduced speed and rejects into minutes?
For reduced speed, take the units you missed by running under the ideal cycle time and multiply by the ideal cycle time, that is the minutes of output you lost. For rejects, multiply the reject count by the ideal cycle time, since a rejected part cost the time to make it. Entering all six losses in the same unit, minutes, is what lets them add up into one honest waterfall.
Which of the six usually costs the most?
On most lines it is the performance pair, small stops and reduced speed, precisely because they are not tracked. Breakdowns get a ticket and setups get a plan, so they are managed. A machine idling twenty seconds at a time, all shift, is nobody's job to notice, and it can quietly out-cost every breakdown on the board.
How do we actually find the hidden losses?
You measure at the machine instead of on paper. The free OEE Tracker logs stops and slow runs as they happen, and Fabrico goes further: it tracks downtime live from the PLC and, where cameras are fitted, puts camera video next to each stop with a suggested cause, and a technician opens the work order from the stop. The OEE calculator and the availability, performance and quality guide show how the same numbers roll up.
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