Your line looks healthy. What is the rolled yield?
First pass yield is how many units clear a single step with no rework. Rolled throughput yield multiplies those steps together, and it is always lower than any one of them. Enter each step's yield and watch a process that passes 95 percent or more at every station still quietly remake a large share of its output. Numbers update as you type.
Your process steps
Enter the first pass yield of each step: units that pass right the first time, before any rework. Set a step to 100% if your process has fewer stages.
How yield collapses step by step
Your rolling yield after each step appears here.
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A yield number is only as good as the count behind it.
Rolled yield is a guess until each step is actually counting passes and fails. The free OEE Tracker logs quality losses alongside stops and speed, so your yield is measured, not estimated, and the worst step stops hiding. When you outgrow it, Fabrico tracks quality losses live from PLCs, IoT sensors or AI cameras and, where cameras are fitted, puts the video of a stop next to its machine data.
Open the free OEE TrackerRolled yield hides which step is bleeding.
When the loss is spread thin across five steps, no single station looks like the problem, so teams inspect defects out instead of removing the cause. Fabrico counts output and rejects per station, so rejected output lowers the Quality factor where it happens, and a technician can open a work order from the stop in the same system. You fix the step, not the symptom.
Book a Fabrico demo See how Fabrico tracks OEEWhy rolled yield is the number that matters
Most plants track yield one step at a time, and one step at a time it usually looks fine: 96, 98, 99 percent all read as healthy. Rolled throughput yield tells the truth about the whole line by multiplying those steps together. Multiplication is unforgiving. Five steps at 96 percent do not average to 96, they compound down to about 81 percent, because a unit has to survive every step to come out good. The gap between the yield you see at each station and the rolled yield you actually ship is the hidden factory: the share of your capacity spent making things twice.
The math
First pass yield for a step is good units divided by units in, before any rework. Rolled throughput yield is the product of every step's first pass yield: RTY = FPY1 times FPY2 times FPY3 and so on. Good units out is units started times RTY, and everything else is rework or scrap. Because each factor is less than one, adding a step can only pull RTY down, never up, which is why long processes with high single-step yields still leak.
Yield is lost step by step on multi-step processes such as circuit board assembly, plating and coating. The guides for the SMT stencil printer, depaneling router, electroplating line, tablet coater and paint booth list the defects each step can add. The method is explained step by step in how to calculate first pass yield, and industry context is on the electronics and medical device OEE and downtime pages.
A worked example: the numbers in the calculator
1,000 units start a shift and pass five steps with first pass yields of 97%, 98%, 96%, 99% and 95%.
- Average of the steps: 97%. It looks fine and means nothing.
- Rolled throughput yield = 0.97 × 0.98 × 0.96 × 0.99 × 0.95 = 85.8%.
- Good first time: 858 of the 1,000 units. The other 142 are scrapped or reworked somewhere along the way.
Where to start: the worst step is step 5 at 95%. Take it to 99% and rolled yield rises to 89.4%, about 36 more good units every shift from one step.
Common mistakes
- Averaging the steps. Yield multiplies through a process, so the average always looks better than the line really is.
- Counting rework as a pass. The unit was not right first time, and the rework cost stays invisible.
- Measuring only at final test. A defect found at the end tells you a unit failed, not which step made it fail. Measure per step.
- Leaving out the steps with no inspection. If a step can make a bad unit, it belongs in the chain, even if the defect is only found later.
How do you calculate rolled throughput yield?
Multiply the first pass yield of every step. Five steps at 97%, 98%, 96%, 99% and 95% give 0.97 × 0.98 × 0.96 × 0.99 × 0.95 = 85.8%, so 858 of 1,000 units come through right first time.
What is the difference between first pass yield and rolled throughput yield?
First pass yield is for one step: good units out of that step without rework, divided by units in. Rolled throughput yield is for the whole process: the product of every step, the chance a unit clears all of them first time.
Should I count reworked units as passing?
No. First pass yield means right the first time, so a unit that needed rework counts as a fail even if it eventually ships. Counting rework as a pass is exactly what hides the hidden factory, because the cost of remaking the unit stays invisible while the yield number looks fine.
How many steps should I include?
Include every step where a unit can be scrapped or sent back, from incoming through final test. Leaving steps out flatters the number. This tool gives you five, which covers most lines; set any you do not use to 100 percent, and combine minor steps if you have more.
How do we actually raise rolled yield?
Find the worst step, remove the cause of its defects, then repeat. Inspecting harder does not raise first pass yield, it only catches more fails after the fact. The scrap rate calculator puts a cost on the losses, and Fabrico tracks quality losses per machine and shift alongside stops, so the worst step is visible.
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