Project Toolkitby Maxime Lab
Scope and Quality · tool 9 of 9

Scope and Quality · tool 9 of 9

Cost of Quality

Cost of Quality: shows that preventing defects usually costs less than fixing them.

Best for: Justifying quality work · Time: 1 hour
Domain: Scope · Focus area: Planning

How it works

Cost of quality has two sides. Conformance is what you spend to get it right: prevention and appraisal. Nonconformance is what you pay for getting it wrong: internal failures, found before delivery, and external failures, found by customers.

  • Prevention: training, standards, design reviews.
  • Appraisal: tests, inspections.
  • Failure: rework, scrap, returns, lost reputation.

How to apply it

  1. List your quality costs in those four groups.
  2. Estimate each from recent work.
  3. Move effort towards prevention.
  4. Track rework as a share of effort.
In practice

Two days of design review may save three weeks of rework in testing.

Pro tip

Track rework. It’s the most honest quality number a team has.

Quick check

A customer returns a faulty product. What cost is that?

Sources

  • PMBOK® Guide, 8th edition, and The Standard for Project Management (PMI, 2025)
  • J. M. Juran, Juran’s Quality Handbook

Last reviewed 2026-11-02 against the PMBOK® Guide, 8th edition · Practitioner review pending · How this guide is made