Critical to Quality
Use when asked to define Critical to Quality (CTQ) requirements in a Six Sigma context — translating customer expectations into measurable product/service characteristics with performance targets — as distinct from the general SQA catalog (see system-quality-attributes) and feeding directly into a dmaic project's Define/Measure stages.
Critical to Quality (CTQ) is a Six Sigma term for a metric that captures a customer requirement in a measurable, quantifiable way — identifying where an organization's processes fall short of customer expectations and can be improved to raise customer satisfaction.
What counts as a CTQ
A specific, measurable characteristic of a product or service that determines customer satisfaction — CTQs can be internal (e.g. a manufacturing process tolerance) or external (e.g. a stated customer requirement), and are identified by analyzing customer feedback, market research, and the organization's own quality-management data (see Voice of the Customer for the customer-feedback side of this identification process).
From identified CTQ to managed metric
- Identify the CTQs — the specific characteristics that actually drive customer satisfaction, grounded in real customer input rather than internal assumption about what customers care about.
- Set performance targets — establish a target for each CTQ, calibrated so meeting it consistently over time actually reflects customer satisfaction, not just an internally convenient number.
- Measure and analyze — track whether targets are being met, and use the data to prioritize process improvements toward the CTQs that are falling short.
Why CTQs matter
They focus the organization on the most important aspects of its product or service — rather than optimizing something that's easy to measure but doesn't actually drive customer satisfaction, CTQs anchor improvement effort to what customers have actually shown they care about. The result, done well: better customer satisfaction and loyalty, increased sales, and improved profitability.
Relationship to DMAIC and system quality attributes
CTQ identification typically happens during a DMAIC project's Define stage (what does the customer actually need) and is tracked through Measure and Control. CTQs are narrower and more customer-facing than System Quality Attributes's full catalog of technical quality attributes — a CTQ is specifically a characteristic customers have shown they care about, whereas the SQA catalog covers technical attributes (like maintainability or observability) that may matter to engineering without being directly customer-visible at all.
Common pitfalls
- CTQs defined from internal assumption rather than real customer input — defeats the whole purpose; see Voice of the Customer for grounding CTQs in actual feedback.
- Setting a target that's easy to hit but doesn't reflect real satisfaction — a CTQ target should be calibrated against what actually satisfies customers, not against whatever the current process can already comfortably achieve.
- Too many CTQs diluting focus — similar to Critical Success Factors's warning about too many CSFs; CTQs should stay to the characteristics that genuinely drive satisfaction, not an exhaustive list of every measurable product attribute.
- No ongoing measurement after initial identification — a CTQ identified once and never tracked again can't actually confirm whether customer expectations continue to be met as the process or product evolves.
Learn more
- DMAIC for the broader Six Sigma methodology CTQ identification fits within.
- Voice of the Customer for grounding CTQs in real customer feedback.
- System Quality Attributes for the broader, more technical quality-attribute catalog CTQs are a customer-focused subset of.