Bug Fix Cost Calculator
Work out what fixing a set of defects costs to fix, retest and release.
What this calculator does
Internal failure cost as defined by the cost-of-quality model: effort spent correcting defects, valued at the organisation's own loaded rate. Defect counts and fix times are the organisation's own measurements.
Inputs and what they mean
- Currency
- — Amounts are shown in the currency you pick. No exchange rate is applied..
- Defects to fix
- — number value.
- Hours to diagnose and fix one defect
- — Your own recorded average..
- Loaded cost per engineer hour
- — number value.
- Retest and review hours per defect (optional)
- — Optional component. Leave at 0 to exclude it from the result..
- Release and deployment cost (optional)
- — Optional component. Leave at 0 to exclude it from the result..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
Hours = Defects × (Hours to fix one + Retest hours per defect); Cost = Hours × Loaded cost per hour + Release and deployment cost
Worked example
120 defects at 5.5 hours each
An internal failure cost built from your own defect data.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Reference: American Society for Quality — Cost of quality — prevention, appraisal and failure costs
Last reviewed:
Common questions
Formula, source and verification
Internal failure cost: the labour spent correcting defects, plus any release cost the correction triggers.
The question it answers: What will it cost us to clear these defects?
The formula
Hours = Defects × (Hours to fix one + Retest hours per defect); Cost = Hours × Loaded cost per hour + Release and deployment cost
- D — Defects to fix
- (defects). Number of defects in scope.
- h — Hours to diagnose and fix one defect
- (h). The organisation's own recorded average.
- t — Retest and review hours per defect
- (h). Optional appraisal effort per defect.
- r — Loaded cost per engineer hour
- (currency/h). Employer cost per engineer hour.
- R — Release and deployment cost
- (currency). Optional cost of shipping the corrections.
Units: Defects; hours; currency.
What kind of calculation this is
Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.
Method
Internal failure cost as defined by the cost-of-quality model: effort spent correcting defects, valued at the organisation's own loaded rate. Defect counts and fix times are the organisation's own measurements.
Assumptions built into the result
- Mathematical: The hours per fix are an average over the defects in scope.
Figures this calculator will never guess for you
- No industry delivery rate, productivity figure, defect rate or cost per line is inserted.
- No optional component is filled in on the user's behalf.
- No cost-of-defect multiplier by development phase is applied.
Limitations
- Counts correction cost only; it does not value the impact of the defects on customers.
- An average over the defects in scope, not a per-defect estimate.
Source and version
- Standard or reference
- Cost of quality — internal failure cost — American Society for Quality (ASQ, Cost of Quality — internal failure cost is the labour and rework spent correcting defects found before delivery.)
- Published source
- American Society for Quality — Quality resources
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Standards or government
- Applies to
- Currency
- Amounts stay in the currency you choose; no exchange rate is applied.
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