Supplier Quality, Development & Audits worked example

Supplier Audit Cost at 61% auditor billable utilization: a worked example in supplier quality, development & audits

Here is what the math looks like when conditions slip. We hold every other input steady and drop auditor billable utilization to 61%, then walk the calculation through step by step. Estimates the fully loaded cost of conducting an on-site supplier quality audit including auditor time and travel.

The inputs for this scenario

  • On-site audit days: 4 days (held at the documented default)
  • Loaded auditor day rate: 1,200 $/day (held at the documented default)
  • Auditor billable utilization: 61 % (the input this scenario stresses; the baseline uses 85)
  • Travel and lodging adder: 1,800 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total audit cost = audit days x day rate x billable utilization% + travel adder.
  • Total supplier audit cost works out to 4,728 $ at these inputs, and this is the headline figure for the scenario.
  • Supplier audit cost per unit works out to 1,182 $ / piece at these inputs.
  • Variable supplier audit cost works out to 2,928 $ at these inputs.
  • Fixed supplier audit cost adder works out to 1,800 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where auditor billable utilization sits at 85% and the headline result is 5,880 $, this scenario comes in 19.59% below the baseline at 4,728 $.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to auditor billable utilization, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It models one audit's direct cost - it excludes the supplier's own time, follow-up re-audits, and the value of risk avoided, so it is a cost estimate, not a return-on-audit analysis.

Results at a glance

  • Total supplier audit cost: 4,728 $ (headline result)
  • Supplier audit cost per unit: 1,182 $ / piece
  • Variable supplier audit cost: 2,928 $
  • Fixed supplier audit cost adder: 1,800 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Supplier Audit Cost calculator, set auditor billable utilization to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.