What is the cost of Quality? (COQ)

By: Sarah Abdallah

The DefinitionWikipedia says: “The concept of quality costs

is a means to quantify the total cost of quality-related efforts and deficiencies.”

“The cost of quality planning, control, assurance and rework.”cio.osu.edu/projects/framework/glossary.html

“The cost of quality is the expense of all the activities within a project to meet quality objectives.”pmpbank.googlepages.com/glossary

The Father of Quality RevolutionPhilip B. Crosby (known as the Father of

Quality Revolution) has written various essays and books on the topic of Quality. He was a local businessman, author, and teacher. His philosophies and concepts helped change the ways business is conducted worldwide.

Examples of his books

Quality is Free…As told by Philip. B Crosby, the cost of quality

has two main components: The cost of good quality (or the cost of conformance) and The cost of poor quality (or the cost of non-conformance)

The Quality Triangle

Quality Triangle RulesIf you want something fast and cheap, it won’t

be of good quality. If you want something of good quality and in good timing, it won’t be cheap. If you want something with good quality and cheap it won’t be fast.

The cost of Poor Quality affects The cost of poor quality affects Internal and

External costs resulting from failing to meet requirements.

Cost of Good Quality affectsCosts for investing in the prevention of non-

conformance to requirements. Costs for appraising a product or service for conformance to requirements.

Cost of Poor Quality: Internal Failure Costs“Internal failure costs are costs that are caused by products or

services not conforming to requirements or customer/user needs and are found before delivery of products and services to external customers.”

Examples would be:-Rework-Delays-Re-designing-Shortages-Failure analysis-Re-testing-Downgrading-Downtime-Lack of flexibility and adaptability

Cost of Good Quality: Prevention Costs Prevention costs are costs of all activities

that are designed to prevent poor quality from arising in products or services.

-Quality planning -Supplier evaluation -New product review -Error proofing -Capability evaluations -Quality improvement team meetings -Quality improvement projects -Quality education and training

Measurement of qualityReliabilityValidityMeasurement errorsCorrelationCausality

SIGMA

What is Six Sigma?A statistics-driven approach to quality control.

Six steps to Six SigmaIdentify the product you create or the service you

provide in other wordsIdentify the customer(s) for your product or service,

and determine what they consider importantIdentify your needsDefine the process for doing your workMistake-proof the process and eliminate wasted efforts Ensure continuous improvement by measuring,

analyzing and controlling the process using “DMAIC”(Define, Measure, Analyze, Improve, Control)