What Is First Pass Yield (FPY)? EDGEBIC Definition and Formula

First pass yield is the fraction of units that pass a quality inspection without rework on their first attempt: if 8 of 10 parts pass QC the first time, first pass yield is 80 percent. It treats both scrap and rework as losses, because a part that had to be reworked did not pass on the first pass even if it was eventually saved. In EDGEBIC the same measure appears as the Quality factor inside Overall Equipment Effectiveness, built from the good, scrap, and rework piece counts that operators log at the kiosk.

This entry is part of the EDGEBIC by User Solutions glossary series; for the broader vocabulary of planning, see the manufacturing glossary. For the general quality-KPI framing, see the first pass yield overview.

How First Pass Yield Works

First pass yield answers one question: of everything a process produced, how much came out right the first time? The formula is good pieces divided by the total of good, scrap, and rework pieces. Scrap is an outright loss; rework is a subtler one, because the part is salvageable but only after a second operation. Counting rework as a failure is what makes first pass yield stricter, and more honest, than a plain accept rate.

The strictness is the point. A shop can hit a 99 percent final accept rate while quietly reworking a quarter of its output, which hides real cost in overtime and delay. First pass yield exposes that by putting rework in the denominator as a first-pass miss.

First pass yield depends entirely on having counts. Without recorded good, scrap, and rework quantities there is nothing to divide, so any honest system either shows a number backed by data or shows nothing at all. EDGEBIC takes the second path when data is absent, which is why quality can read "n/a" rather than a comforting but invented 100 percent.

A Concrete Example

Take a CNC machine over a five-day window. The kiosk production punches record:

First pass yield = good divided by (good + scrap + rework) times 100 = 105 divided by (105 + 3 + 2) times 100 = 95.5 percent.

Now place that inside OEE. For the same machine, availability was 80 percent (it lost one of five scheduled days) and performance was 85.9 percent (it ran at about 86 percent of theoretical throughput). OEE multiplies the three:

OEE = 0.80 times 0.859 times 0.955 = 65.5 percent.

The 95.5 percent quality is the healthiest of the three factors; the biggest lever here is the 20 percent availability loss. But quality only entered the OEE at all because the kiosk supplied piece counts. Strip the punches out and quality reads "n/a", and OEE with it.

How EDGEBIC Uses First Pass Yield

First pass yield surfaces as the Quality factor in the Overall Equipment Effectiveness (OEE) report. The service reads good, scrap, and rework counts from production punches, computes quality per work center, and multiplies it with availability and performance to produce OEE. Two behaviors follow directly from the data model:

• Quality is null (shown as "n/a") when no production punches exist. This is a deliberate design choice: fabricating 100 percent would overstate OEE, so a machine without kiosk data shows no quality and no OEE rather than a misleading full score.
• The dashboard's Quality tile stays Offline until a dedicated defect or scrap log exists. The book is explicit that an older dashboard tile once computed on-time delivery and merely labeled it "First Pass Yield"; the current tile is honest about being Offline rather than showing the wrong number.

Getting real first pass yield therefore comes down to capturing piece outcomes on the floor. Once operators log actual hours and pieces with good and reject counts at the kiosk, the Quality and OEE columns fill in on the next report load.

Read first pass yield with OEE, whose three factors it partners, and see the EDGEBIC reports guide for how the OEE pane sits among the eighteen report views. For the throughput side of the same machine, see throughput in manufacturing.