Here is an uncomfortable truth about quality metrics: a process where every step passes 95% of units can still deliver good product less than 80% of the time. Each step looks fine in isolation; the process as a whole quietly bleeds yield. Rolled throughput yield (RTY) is the metric that exposes this, and it reveals losses that OEE's quality factor, and your final inspection numbers, can completely miss.
RTY shows the true odds of a unit passing every step right first time.
Rolled throughput yield is the probability that a unit passes through an entire multi-step process with no defects and no rework, right first time at every step. It is calculated by multiplying the first-pass yield of each individual step together. Where final-yield numbers only ask "did it eventually ship good?", RTY asks "did it get there without any hidden rework along the way?"
RTY = FPY(step 1) × FPY(step 2) × ... × FPY(step n), where each step's first-pass yield is good-first-time units divided by units entering that step.
Example: a four-step process with first-pass yields of 98%, 95%, 97% and 96%. Final inspection might suggest things look healthy, but RTY = 0.98 × 0.95 × 0.97 × 0.96 ≈ 86.6%. More than 13% of units needed rework somewhere, even though no single step looked alarming. Add more steps and the compounding gets brutal.
Traditional yield measures only the end of the line, so units that were reworked, retested or quietly fixed mid-process still count as "good." That hides an entire shadow operation of rework, the hidden factory, that consumes time, capacity and cost without ever showing up in final yield. RTY makes that loss visible by penalising every defect at the step where it occurs.
OEE includes a quality factor, but it is typically measured at the machine or station. RTY looks across the whole multi-step process and captures the compounding effect of rework between steps. Used together, OEE tells you how effectively each asset runs, and RTY tells you how cleanly the product flows through the entire process. Both rely on the same discipline as first-pass yield, and both feed into the true cost of poor quality.
Calculating RTY properly needs first-pass (not final) results captured at every step, which is exactly the data most plants do not record, because rework gets fixed quietly and never logged. That uncaptured rework is dark data. Capturing pass/fail at each step automatically is what makes RTY real rather than theoretical.
Fabrico captures quality and production data step by step in real time, so first-pass results, and the rework that usually hides, are recorded rather than lost. That lets you see true rolled throughput yield alongside OEE, expose the hidden factory of rework, and target the steps that quietly erode your real yield.
The probability that a unit passes through every step of a process with no defects or rework, calculated by multiplying each step's first-pass yield together.
OEE quality is usually measured per machine or station; RTY looks across the whole multi-step process and captures the compounding effect of rework between steps.
Because final yield counts reworked units as good, hiding the rework. RTY penalises every defect at its source, revealing the hidden factory.
See the yield your final inspection hides. Fabrico captures first-pass results step by step so you can measure true RTY alongside OEE. Book a demo today.
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