How do you calculate PCS cabinet FAT yield?

Divide cabinets passing FAT by total cabinets entering FAT and multiply by 100. With 47 of 50 cabinets passing, yield is 94%.

What is a good FAT first-pass yield for PCS cabinets?

World-class first-pass yield is typically 95% or higher for mature PCS production. At 94% against a 95% target, this example sits just 1 point short, signaling a process that is close but needs attention.

What does the yield gap to target mean?

It is the difference in percentage points between actual and target yield. A 94% yield against a 95% target gives a 1-point gap, a small but real shortfall worth root-causing.

Why use first-pass yield instead of final yield?

First-pass yield exposes process problems that rework hides. A cabinet that fails then passes after fixing still counts as a first-pass failure, which is exactly the signal quality engineers need.

How many cabinets should I start to ship 47?

At 94% first-pass yield you would start about 50 to net 47 passing on first pass, which is exactly the case here. If rework recovers most failures your start quantity can be lower.

What typically causes PCS cabinet FAT failures?

Common culprits are firmware and parameter mismatches, wiring and torque defects, control board faults, and protection setting errors. Tracking failure modes alongside this yield turns the number into corrective action.

Grid-Scale Battery Energy Storage Systems calculator

BESS PCS Cabinet Factory Acceptance Yield Calculator

First-pass yield at factory acceptance test (FAT) is the cleanest signal of build quality for power conversion system (PCS) cabinets, the inverters and switchgear that turn a battery's DC into grid-compliant AC. This calculator divides cabinets that pass FAT by total cabinets tested to give a first-pass yield rate, then compares it against your target to show the gap in percentage points. BESS integrators, PCS manufacturers, and quality engineers use it to track production health, trigger corrective action, and forecast how many cabinets to start to hit a delivery commitment. A yield that drifts below target quietly inflates rework cost and threatens ship dates.

What this calculator does

Calculate power conversion system cabinet first-pass yield at factory acceptance test for grid-scale BESS production by comparing PCS cabinets passing all FAT checks against total cabinets tested and measuring the gap to the yield target.
Use it when the PCS cabinet factory acceptance test line needs a clean yield rate for the weekly quality review and you need to decide whether to escalate an inverter power stage or control board issue.
It computes the first-pass FAT yield rate for PCS cabinets and the gap in percentage points between that rate and your target.

Formula used

PCS cabinet FAT yield rate = PCS cabinets passing FAT / total PCS cabinets entering FAT x 100
PCS cabinet yield gap to target = FAT yield rate - target PCS cabinet yield rate

Inputs explained

PCS cabinets passing factory acceptance test:
Total PCS cabinets entering factory acceptance test:
Target PCS cabinet yield rate:

How to use the result

Use it on the production floor to monitor build quality, set rework expectations, and decide whether yield is trending toward or away from target.
It measures first-pass yield only and does not account for cabinets that pass after rework, so it can understate final shippable yield while still flagging process problems.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
Industrial electricity averages 8.66 cents per kWh across the U.S. (EIA, Apr 2026), up 5.5% from a year earlier. Energy-intensive steps carry this directly into unit cost.
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate PCS cabinet FAT yield? Divide cabinets passing FAT by total cabinets entering FAT and multiply by 100. With 47 of 50 cabinets passing, yield is 94%.
What is a good FAT first-pass yield for PCS cabinets? World-class first-pass yield is typically 95% or higher for mature PCS production. At 94% against a 95% target, this example sits just 1 point short, signaling a process that is close but needs attention.
What does the yield gap to target mean? It is the difference in percentage points between actual and target yield. A 94% yield against a 95% target gives a 1-point gap, a small but real shortfall worth root-causing.
Why use first-pass yield instead of final yield? First-pass yield exposes process problems that rework hides. A cabinet that fails then passes after fixing still counts as a first-pass failure, which is exactly the signal quality engineers need.
How many cabinets should I start to ship 47? At 94% first-pass yield you would start about 50 to net 47 passing on first pass, which is exactly the case here. If rework recovers most failures your start quantity can be lower.

Last reviewed 2026-05-12.