Glossary · Manufacturing systems
First-pass yield (FPY)
Also known as: FPY, First-time yield, First-time-right rate
German: Gutquote im ersten Durchlauf (FPY)
In manufacturing, first-pass yield (FPY) is the proportion of units that pass a process step or the whole process correctly the first time, without rework, repair or scrap.
- Manufacturing systems
- Standards
In one sentence
First-pass yield (FPY) is the share of units that pass a process correctly the first time, without rework, repair or scrap.
Example
Of 1,000 circuit boards, 962 pass the in-circuit test first time, so the test step's FPY is 96.2 percent.
How it applies
- Quality: FPY shows hidden rework that final yield figures conceal. A line can ship 99 percent good units while reworking 15 percent of them.
- Analysis: For a multi-step process, the rolled throughput yield multiplies the FPYs of all steps. ISO 22400-2 defines FPY among its key performance indicators for manufacturing operations management.
- Operation: FPY depends on reliable defect detection at each step; weak inspection makes FPY look better than it is.
- Documentation: Define what counts as a pass, which retests are allowed and at which step FPY is measured. Quality documentation should record these definitions so trends remain comparable.
First-pass yield vs. scrap rate
The Scrap rate counts units that are discarded. FPY also counts units that are reworked and later pass. FPY is therefore always equal to or lower than the yield after rework.