How do you calculate component attrition cost?

Multiply placements by average part cost by the attrition rate for the variable cost, then add fixed shortage or excess-buy cost. Here 420,000 placements at $0.075 each times 1.8% is $567, plus $1,200 fixed, for $1,767 total.

What is a typical SMT component attrition rate?

Attrition allowances commonly run 0.5-3% depending on part size, feeder type, and process maturity, with tiny 0201 passives at the higher end. The example uses 1.8%.

Why is the average component cost shown so low?

The displayed $0.0042 average is total attrition cost spread across all 420,000 placements, not the input part price. It blends the $0.075 part cost and 1.8% attrition with the fixed cost into a per-placement figure.

What does the shortage handling cost represent?

It is the fixed cost of expediting parts or buying extra reels to cover attrition-driven shortages — $1,200 here. It does not scale with placements but is real overhead on top of scrapped-part value.

How does attrition affect how many parts I order?

You order net build demand plus an attrition buffer. At 1.8% on 420,000 placements you lose roughly 7,560 parts to attrition, which this model values at $567 in scrapped components alone.

What is the variable versus total attrition cost here?

Variable attrition cost is $567 (420,000 times $0.075 times 1.8%). Adding the $1,200 shortage-handling cost gives the $1,767 total.

Appliance Electronics & Control Boards calculator

Component Attrition Cost Calculator

Component attrition cost is the dollar value of SMT and through-hole parts lost to placement scrap, feeder spillage, tombstoning, and damaged components during an appliance control board build. Materials and SMT process engineers track it because attrition drives the buffer quantity you must order above net build demand — order too little and you stop the line chasing shortages, too much and you carry dead inventory. The cost has a variable piece tied to placements times part cost times attrition rate, plus a fixed piece for expediting shortages or buying excess reels. This calculator combines both so you can set realistic attrition allowances and see what scrap is actually costing per build.

What this calculator does

Estimate appliance control board component attrition cost from component placements, average component cost, attrition rate, and fixed shortage handling cost.
a procurement lead or estimator needs to include realistic component attrition in a control board quote or production plan
It computes variable component attrition cost as placements times average part cost times the attrition rate, then adds fixed shortage-handling or excess-buy cost for the total.

Formula used

Variable component attrition cost = components placed or issued × average component cost × expected component attrition
Total component attrition cost = variable attrition cost + shortage handling or excess buy cost

Inputs explained

Components placed or issued:
Average component cost:
Expected component attrition:
Shortage handling or excess buy cost:

How to use the result

Use it when setting buffer quantities, costing a board BOM, or quantifying the dollar impact of an attrition rate on a high-placement appliance board.
It applies one blended part cost and attrition rate across all placements; in reality fine-pitch and high-value parts attrit differently than passives, so blended figures can mask hotspots.

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 component attrition cost? Multiply placements by average part cost by the attrition rate for the variable cost, then add fixed shortage or excess-buy cost. Here 420,000 placements at $0.075 each times 1.8% is $567, plus $1,200 fixed, for $1,767 total.
What is a typical SMT component attrition rate? Attrition allowances commonly run 0.5-3% depending on part size, feeder type, and process maturity, with tiny 0201 passives at the higher end. The example uses 1.8%.
Why is the average component cost shown so low? The displayed $0.0042 average is total attrition cost spread across all 420,000 placements, not the input part price. It blends the $0.075 part cost and 1.8% attrition with the fixed cost into a per-placement figure.
What does the shortage handling cost represent? It is the fixed cost of expediting parts or buying extra reels to cover attrition-driven shortages — $1,200 here. It does not scale with placements but is real overhead on top of scrapped-part value.
How does attrition affect how many parts I order? You order net build demand plus an attrition buffer. At 1.8% on 420,000 placements you lose roughly 7,560 parts to attrition, which this model values at $567 in scrapped components alone.

Last reviewed 2026-05-12.