First-Pass Yield (FPY)

Excel Formulas › Manufacturing & Operations

All versionsPRODUCT

First-pass yield is the share of units that pass without rework — tougher and more honest than final yield. For a multi-step process, multiply each step’s yield for the rolled throughput yield.


Quick formula: FPY at one step:
=units_passed_first_time / units_in
Units that passed without rework over units entering. Multiply step FPYs for the whole-process yield.

Functions used (tap for the full reference guide):

The example

Steps at 98%, 97%, 99%.

AB
1ItemValue
2Step FPYs98/97/99%
3Rolled→ ~94.1%

The formula

The formula:

=units_passed_first_time / units_in // passed-first-time ÷ in

How it works

How it works:

  1. Step FPY = units passing without rework ÷ units entering — reworked units don’t count as first-pass.
  2. It’s stricter than final yield, which counts reworked-then-passed units as good.
  3. For a multi-step process, rolled throughput yield = PRODUCT(step_FPYs).
  4. Three 98% steps roll to ~94% — small per-step losses compound across the line.

Rolled yield exposes hidden rework. Each step might report 97–99% “yield,” looking fine — but multiplied across ten steps that’s only ~80% making it through first time. The gap between final yield and rolled FPY is the “hidden factory” of rework. PRODUCT(step_yields) in one cell surfaces it.

Try it: interactive demo

Live demo

Step yields (comma-separated %).

Rolled FPY:

Variations

Rolled throughput yield

Multiply steps:

=PRODUCT(step_yield_range)

vs final yield

The rework gap:

=final_yield - rolled_FPY

Defects per step

Failed first time:

=units_in - units_passed_first_time

Pitfalls & errors

First-time only. Reworked-then-passed units are not first-pass.

Multiply, don’t average. Rolled yield is the product of step yields.

Percent as decimal. 98% is 0.98 in PRODUCT.

Practice workbook

📊
Download the free First-Pass Yield (FPY) practice workbook
An FPY sheet with the rolled, vs-final, and defects variants, plus 4 challenges with answers. No sign-up required.

Frequently asked questions

How do I calculate first-pass yield in Excel?
Per step: =units_passed_first_time / units_in. For the whole process, multiply the step yields: =PRODUCT(step_FPYs).
How is FPY different from final yield?
FPY counts only units that passed without rework; final yield includes reworked-then-passed units, so it looks higher.
Why do step yields roll up so low?
They multiply — three 98% steps give ~94%, exposing the hidden rework across the line.

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Function references: PRODUCT