Glossary
FPY full form: First Pass Yield, explained
FPY stands for First Pass Yield — the share of parts that came out right on the first attempt, with no rework and no scrap.
Updated October 2026 · ThingConnect team
What FPY measures
FPY = Good parts on the first attempt ÷ Total parts started, expressed as a percentage. A part that needed rework, even if it eventually passed inspection, does not count as a first-pass good part — FPY is specifically about getting it right once, not eventually.
That distinction is the whole point of tracking it separately from a plain scrap rate. Scrap rate only sees parts thrown away. A batch where every reject gets reworked and ships can show 0% scrap and still be burning hours on rework that nobody is measuring — FPY is what surfaces that hidden cost.
A worked example
One batch, one CNC operation:
Total parts started
- Value
- 150
Passed inspection first time
- Value
- 141
Reworked or scrapped on first pass
- Value
- 9
| Input | Value |
|---|---|
| Total parts started | 150 |
| Passed inspection first time | 141 |
| Reworked or scrapped on first pass | 9 |
FPY = 141 ÷ 150 = 94.0%. If all 9 were eventually reworked and shipped, the final yield would read 100% — a number that hides the rework hours entirely. FPY is the one that would have flagged it.
Run your own batch numbers in the FPY calculator, or see how FPY sits inside the full Quality component in the OEE guide.
Questions
Frequently asked questions
FPY stands for First Pass Yield (also called throughput yield). It's the percentage of parts that came out right the first time — no rework, no scrap, no second pass through an operation.
No, they're inverses of different things. Scrap rate counts only parts thrown away; FPY also counts parts that were reworked and eventually passed. A part reworked twice and finally accepted hurts FPY but may never show up as scrap.
There's no universal target — a job shop running first-off setups on every batch will run lower than a repeat-part production line, and that's not a defect. The useful comparison is the same part number and the same machine, over time, not FPY against an industry figure.
FPY is effectively the Quality component of OEE, scoped to first-pass acceptance rather than final acceptance after rework. A low FPY with a high final-yield number usually means rework is quietly eating capacity that OEE's Quality term won't show you on its own.