Why is my first-pass yield lower than the lot record's yield?

Because the quantity released on the lot record includes reworked devices. First-pass yield counts only devices that passed every inspection and test the first time, so rework shows as the gap to final yield.

Should destructive test samples count as rejects?

No. Devices pulled for seal strength, sterility or other destructive tests were never meant to ship. Leave them out of devices started so they neither lower nor raise the yield.

When does a drop in yield need an investigation?

When the reject rate rises beyond your process's known capability. FDA's example is a molding process whose normal 5% reject rate rises to 10%; that process nonconformance must be investigated.

How do I get yield for a line with several test steps?

Multiply each step's first-pass yield to get rolled throughput yield. Run each step here with its own devices in and first-pass rejects, then multiply the results; the lowest step is the one to fix first.

MedTech Manufacturing calculator

Medical Device First-Pass Yield Calculator

Score a device lot's first-pass yield against your target and see how much rework the lot record hides. You need devices started, first-pass rejects and rejects reworked and accepted.

What this calculator does

First-pass yield, final yield and the gap to your target for a device lot, from devices started, first-pass rejects and reworked rejects.

Formula used

First-pass yield = (devices started − first-pass rejects) ÷ devices started × 100
Final yield = (devices started − first-pass rejects + rejects reworked and accepted) ÷ devices started × 100
Yield gap to target = target first-pass yield − first-pass yield
Devices short of target = devices started × target ÷ 100 − devices accepted first pass, rounded up, not below zero
Rejects not recovered = first-pass rejects − rejects reworked and accepted

Inputs explained

Devices Started: Work order quantity, excluding destructive test samples.
First-Pass Rejects: Devices failing any inspection or test on the first attempt, counted once.
Rejects Reworked and Accepted: Rejects that passed retest after documented rework, from the lot record.
Target First-Pass Yield: From your control plan, validation report or quality objective.

How to use the result

Best suited to lot close-out yield review, monthly yield trend for management review, measuring the rework load on a new line.
Rejects not recovered include devices on hold or accepted by concession; close material review before reading them as scrap. A line-level yield hides the weakest step; multiply step yields for rolled throughput yield.

Current U.S. benchmarks

U.S. manufacturing runs at 75.7% of capacity with new factory orders at $663B per month (Federal Reserve and Census, Aug 2026).
The U.S. has 8,825 medical equipment and supplies establishments employing about 308,388 workers (Census County Business Patterns, 2023).

Common questions

Why is my first-pass yield lower than the lot record's yield? Because the quantity released on the lot record includes reworked devices. First-pass yield counts only devices that passed every inspection and test the first time, so rework shows as the gap to final yield.
Should destructive test samples count as rejects? No. Devices pulled for seal strength, sterility or other destructive tests were never meant to ship. Leave them out of devices started so they neither lower nor raise the yield.
When does a drop in yield need an investigation? When the reject rate rises beyond your process's known capability. FDA's example is a molding process whose normal 5% reject rate rises to 10%; that process nonconformance must be investigated.
How do I get yield for a line with several test steps? Multiply each step's first-pass yield to get rolled throughput yield. Run each step here with its own devices in and first-pass rejects, then multiply the results; the lowest step is the one to fix first.

Last reviewed 2026-10-01.