How do you calculate ICT test capacity?

Multiply boards per fixture cycle by available fixture cycles for gross capacity, then multiply by tester uptime and first-pass yield. With 2 boards per cycle over 1,250 cycles at 90% uptime and 96% yield, 2,500 gross boards become 2,160 usable tested boards per shift.

What is a good first-pass yield at in-circuit test?

Mature control-board ICT typically sees 95-98% first-pass yield; the 96% default is realistic. Lower numbers usually point to upstream solder defects, marginal components, or fixture contact problems rather than the test program itself.

Why does ICT often become the line bottleneck?

ICT fixtures are frequently single- or double-up while SMT runs 6-up or 8-up panels, so test cycles per board are much higher. If usable ICT capacity falls below your SMT throughput, test caps the line regardless of how fast boards are placed.

What is the difference between boards held for retest and boards lost to downtime?

Downtime at 90% removes 250 boards of capacity outright. The 4% first-pass failure holds 90 boards for debug or retest, which may still pass on a second pass but do not clear first time. Here the two losses are 250 and 90 boards respectively.

How do I find available ICT fixture cycles per shift?

Divide shift length by the per-board test time including load, contact, test, and unload, then multiply by boards per fixture. Enter the resulting cycle count before applying uptime.

Can I improve ICT capacity without buying another tester?

Often yes. Moving to a 2-up or 4-up fixture multiplies boards per cycle, and trimming test program runtime or fixture actuation time raises available cycles. Both lift the 2,160 usable figure before any capital spend on a second tester.

Appliance Electronics & Control Boards calculator

ICT Test Capacity Calculator

ICT test capacity is the number of control boards your in-circuit test station can clear per shift after tester downtime and first-pass test failures are accounted for. Test engineers and production planners in appliance electronics use it to confirm that test does not bottleneck a fast SMT line and to size fixture and tester needs for a new program. It matters because ICT is frequently the hidden constraint downstream of placement: a single-up bed-of-nails fixture and a few percent of debug holds can cap a whole line's shippable output. This model turns fixture cycle time and yield into a defensible good-board-per-shift number.

What this calculator does

Estimate in-circuit test capacity for appliance control boards from boards per fixture cycle, available cycles, tester uptime, and passable test yield.
a test engineer or production planner needs to verify whether ICT fixtures can keep up with PCB assembly output
It computes good tested boards per shift by multiplying boards per fixture cycle by available cycles, then derating for tester uptime and first-pass ICT yield.

Formula used

Gross ICT board capacity = boards tested per fixture cycle × available ICT fixture cycles
Usable ICT test capacity = gross capacity × ICT tester uptime × first-pass ICT yield

Inputs explained

Boards tested per ICT fixture cycle:
Available ICT fixture cycles:
ICT tester uptime:
First-pass ICT yield:

How to use the result

Use it when balancing ICT against SMT output, planning fixture quantity for a new board, or diagnosing a test bottleneck.
It assumes uniform test time per board; boards with long boundary-scan or programming steps inside the ICT cell will lower effective cycles below the entered figure.

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).
Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).
The U.S. has 11,261 computer and electronic products establishments employing about 815,443 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate ICT test capacity? Multiply boards per fixture cycle by available fixture cycles for gross capacity, then multiply by tester uptime and first-pass yield. With 2 boards per cycle over 1,250 cycles at 90% uptime and 96% yield, 2,500 gross boards become 2,160 usable tested boards per shift.
What is a good first-pass yield at in-circuit test? Mature control-board ICT typically sees 95-98% first-pass yield; the 96% default is realistic. Lower numbers usually point to upstream solder defects, marginal components, or fixture contact problems rather than the test program itself.
Why does ICT often become the line bottleneck? ICT fixtures are frequently single- or double-up while SMT runs 6-up or 8-up panels, so test cycles per board are much higher. If usable ICT capacity falls below your SMT throughput, test caps the line regardless of how fast boards are placed.
What is the difference between boards held for retest and boards lost to downtime? Downtime at 90% removes 250 boards of capacity outright. The 4% first-pass failure holds 90 boards for debug or retest, which may still pass on a second pass but do not clear first time. Here the two losses are 250 and 90 boards respectively.
How do I find available ICT fixture cycles per shift? Divide shift length by the per-board test time including load, contact, test, and unload, then multiply by boards per fixture. Enter the resulting cycle count before applying uptime.

Last reviewed 2026-05-12.