How do you calculate inspection burden per assembly?

Multiply the assembly count by the per-unit inspection cost and the chargeable factor, add fixed setup cost, then divide by the count. With 100 units at $45, 80% chargeable and $250 fixed, the total is $3,850 or $38.50 per assembly.

What drives the fixed portion of inspection burden?

Test-equipment calibration, hi-pot setup, first-article checks and inspection fixturing that happen once per run regardless of volume. In the example the $250 fixed cost adds $2.50 to each of the 100 assemblies.

What is a good chargeable inspection portion?

The chargeable factor reflects how much of the nominal per-unit inspection cost is actually billed or absorbed — 80% is typical when some checks overlap or are sampled rather than performed on every unit. A 100% factor means full inspection on every assembly.

Why is inspection burden so high on small switchgear runs?

Fixed calibration and setup cost spreads over fewer units. The same $250 that adds $2.50 per unit across 100 assemblies adds $25 per unit across only 10, which can swamp the variable test cost.

Inspection burden vs cost of quality — are they the same?

Inspection burden is the appraisal slice: the cost of checking and testing conforming product. Full cost of quality also includes prevention, internal failure (rework, scrap) and external failure (returns), so it is broader than this figure.

Switchgear, Panelboards & Electrical Distribution calculator

Inspection Burden Calculator

Inspection burden is the loaded quality cost carried by each switchgear or panelboard assembly — the dielectric tests, torque audits, continuity checks and paperwork that a unit must pass before it ships. Cost accountants and quality managers use it to see the true per-assembly overhead of inspection and to make sure that cost is recovered in the sell price. On regulated distribution gear, inspection is not optional, so it behaves like a fixed burden that a shop must absorb or bill. The calculator separates the variable per-assembly test cost from the fixed calibration and setup cost, which is where inspection economics on small runs quietly break down.

What this calculator does

Inspection burden is the loaded quality cost carried by each switchgear or panelboard assembly — the dielectric tests, torque audits, continuity checks and paperwork that a unit must pass before it ships.
Use it when inspection burden in switchgear, panelboards and electrical distribution is being put through a switchgear, panelboards and electrical distribution weighted-cost review.
It multiplies the number of assemblies by the per-unit inspection cost and a chargeable factor, adds fixed calibration/setup cost, and reports total and per-assembly burden.

Formula used

Inspection Burden cost = quantity × rate × capture factor + fixed cost
Per-unit inspection burden = total cost ÷ quantity

Inputs explained

Assemblies passing through inspection:
Inspection labor & test cost per assembly:
Chargeable inspection portion:
Fixed calibration & setup cost:

How to use the result

Use it when costing the quality function into a switchgear quote, allocating inspection overhead across a run, or judging whether a small batch can absorb its fixed test-setup cost.
The chargeable factor is a single percentage, so it won't separately model a re-inspection loop on failed units, which can add cost that scales with defect rate rather than volume.

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.
On-highway diesel averages $4.58 per gallon this week (EIA), trending down over recent periods. Truck tonnage is up 3.4% year over year (ATA via FRED).
The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate inspection burden per assembly? Multiply the assembly count by the per-unit inspection cost and the chargeable factor, add fixed setup cost, then divide by the count. With 100 units at $45, 80% chargeable and $250 fixed, the total is $3,850 or $38.50 per assembly.
What drives the fixed portion of inspection burden? Test-equipment calibration, hi-pot setup, first-article checks and inspection fixturing that happen once per run regardless of volume. In the example the $250 fixed cost adds $2.50 to each of the 100 assemblies.
What is a good chargeable inspection portion? The chargeable factor reflects how much of the nominal per-unit inspection cost is actually billed or absorbed — 80% is typical when some checks overlap or are sampled rather than performed on every unit. A 100% factor means full inspection on every assembly.
Why is inspection burden so high on small switchgear runs? Fixed calibration and setup cost spreads over fewer units. The same $250 that adds $2.50 per unit across 100 assemblies adds $25 per unit across only 10, which can swamp the variable test cost.
Inspection burden vs cost of quality — are they the same? Inspection burden is the appraisal slice: the cost of checking and testing conforming product. Full cost of quality also includes prevention, internal failure (rework, scrap) and external failure (returns), so it is broader than this figure.

Last reviewed 2026-05-12.