First Pass Yield (FPY): Formula & Example
Definition
First pass yield (FPY) is the percentage of units that pass a process step correctly the first time, without rework, repair or scrap. FPY = units passed first time ÷ units entering the step × 100.
| Term | First pass yield (FPY) |
|---|---|
| In Hindi | प्रथम पास उपज (FPY) |
| Area | Production & quality |
| Search phrase | first pass yield |
| Try it | OEE calculator |
प्रथम पास उपज (FPY) — हिंदी में अर्थ
फर्स्ट पास यील्ड उन इकाइयों का प्रतिशत है जो किसी प्रक्रिया चरण को पहली बार में ही सही पास करती हैं, बिना दोबारा काम, मरम्मत या स्क्रैप के। FPY = पहली बार पास इकाइयाँ ÷ चरण में आई इकाइयाँ × 100।
FPY vs final yield vs RTY
Final yield counts good units at the end, including reworked ones, so it hides the cost of rework. FPY counts only units right first time, so it exposes the hidden factory — the extra labour, machine time and inspection spent fixing defects.
Rolled throughput yield (RTY) multiplies the FPY of each step to show the chance of a unit going through the whole line with no defect at all. Three steps at 95%, 98% and 97% give RTY = 0.95 × 0.98 × 0.97 = 90.3%.
Improving FPY
Record rework and scrap against the operation and reason — not just the final count — so the worst step is visible. Then use Pareto analysis to pick the biggest defect, root cause analysis to fix it, and poka-yoke or a standard operating procedure to keep it fixed. FPY also feeds the quality factor of OEE.
Example
1,000 brackets enter welding: 940 pass first time, 40 are reworked and then pass, 20 are scrapped. FPY = 940 ÷ 1,000 = 94%. Final yield = 980 ÷ 1,000 = 98% — the 4-point gap is rework you are paying for.
Related tools and guides
Frequently asked questions
What is the formula for first pass yield?
FPY = units that pass first time without rework ÷ units entering the process × 100.
What is the difference between FPY and RTY?
FPY is for one step; RTY multiplies the FPYs of all steps to give the defect-free yield of the whole process.
Is first pass yield the same as first time right?
Yes, 'first time right' (FTR) is the same idea and is widely used in Indian plants.
What is a good first pass yield?
It depends on the process, but most plants aim for 95%+ per step; anything lower means significant hidden rework.
Related terms
- 5 Whys (root cause analysis)The 5 Whys is a root cause analysis technique in which a team asks 'why?' repeatedly — typically about five times — starting from a problem, until it reaches a cause that, if fixed, stops the problem coming back.
- 5S5S is a workplace organisation method with five steps: Sort (Seiri), Set in order (Seiton), Shine (Seiso), Standardise (Seiketsu) and Sustain (Shitsuke).
- CAPA (Corrective and Preventive Action)CAPA stands for Corrective and Preventive Action — a structured process to find the root cause of a quality problem, fix it so it does not recur (corrective), and stop similar problems before they occur (preventive).
- DMAIC (Six Sigma)DMAIC — Define, Measure, Analyse, Improve, Control — is the five-step, data-driven problem-solving method used in Six Sigma to improve an existing process by finding and removing the root causes of defects and variation.
- Fishbone diagram (Ishikawa)A fishbone diagram, also called an Ishikawa or cause-and-effect diagram, lays out all the possible causes of a problem in categories along the 'bones' of a fish whose head is the problem, so that a team can brainstorm and then test the likely ones.
- Job workJob work means processing of goods belonging to another registered person (the principal) — such as machining, plating, painting or heat treatment. Under GST, the principal can send goods to a job worker on a challan without paying tax, if they come back in time.