Voice of the Customer
Capture expressed, implied and latent needs in customer language. Record source, context, stakeholder, evidence and importance rather than immediately converting every statement into a solution.
Special Processes Institute
sp-i.org
Quality Function Deployment Report
Quality Function Deployment & House of Quality
Learn and apply Quality Function Deployment as a structured method for translating the Voice of the Customer into prioritised engineering characteristics, measurable targets, product requirements, part characteristics, process controls and production assurance. Build a complete House of Quality, calculate weighted technical priorities, document correlations and trade-offs, benchmark performance, save projects as JSON, load a comprehensive aerospace example and create a professional PDF-ready report.
Customer-focused design Traceable requirements Evidence-based priorities
QFD
Requirements deployment
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Customer requirements
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Technical characteristics
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Highest technical priority
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Project completeness
What Quality Function Deployment Means
A disciplined route from customer language to controlled product and process characteristics.
Quality Function Deployment (QFD) is a cross-functional planning method used to identify customer needs, prioritise them, translate them into measurable technical requirements and deploy those requirements through design, parts, processes and production controls. Its best-known matrix is the House of Quality.
Technical correlations and trade-offs
Customer Requirements — WHATs
Engineering Characteristics — HOWs
Customer & Competitive Benchmarking
Relationship Matrix
Strong 9 · Medium 3 · Weak 1
Strong 9 · Medium 3 · Weak 1
Technical priorities · direction of improvement · targets · difficulty · ownership
Engineering Translation
Convert needs into measurable, controllable characteristics such as mass, strength, reliability, coating thickness, response time, corrosion performance or maintainability.
Relationship Analysis
Judge how strongly each technical characteristic influences each customer requirement. The matrix highlights where engineering effort creates the greatest customer value.
Deployment
Cascade high-priority technical characteristics into part requirements, process parameters, control plans, verification, validation, supplier controls and production readiness.
Product PlanningCustomer needs → technical characteristics
Part DeploymentTechnical characteristics → component requirements
Process PlanningComponent requirements → process controls
Production PlanningControls → inspection, monitoring and assurance
Strong QFD practice: uses authentic customer evidence, avoids vague technical measures, includes diverse functions, records uncertainty and maintains traceability into verification and control.
Common failure modes: treating the matrix as a scoring exercise, using assumed customer needs, duplicating requirements, choosing solution-biased HOWs, scoring every relationship and failing to deploy outputs.
Important principle: the matrix supports judgement; it does not replace technical competence, regulatory compliance, safety analysis, design review, risk management or formal verification and validation.
QFD Method and Good Practice
1. Define Scope
Identify the product, service, programme, lifecycle stage, customer segments, decision boundaries and outputs expected from the QFD study.
2. Capture Customer Needs
Use interviews, complaints, warranty, surveys, observation, contracts, standards, operational data and stakeholder workshops.
3. Structure the WHATs
Consolidate duplicates, preserve meaning, separate needs from solutions and organise requirements into logical themes.
4. Weight Importance
Use a consistent scale, usually 1–5 or 1–10. Consider stated importance, customer dissatisfaction, strategic importance and risk.
5. Define HOWs
Select measurable characteristics that the organisation can influence. State units, direction of improvement and technical ownership.
6. Score Relationships
Use 9, 3, 1 and blank for strong, medium, weak and no meaningful relationship. Require a rationale for significant judgements.
7. Analyse the Roof
Identify positive synergy and negative trade-offs between technical characteristics. Negative correlations often reveal design risk.
8. Benchmark and Target
Compare current and competitor performance where reliable evidence exists, then define realistic but challenging technical targets.
9. Deploy and Control
Carry priority outputs into DFMEA, verification, special-process validation, supplier requirements, control plans and production monitoring.
Recommended Scales
| Element | Scale | Interpretation |
|---|---|---|
| Customer importance | 1–5 | 1 = low importance; 5 = essential or critical to customer satisfaction. |
| Relationship | 9 / 3 / 1 / blank | Strong, medium, weak or no meaningful influence. |
| Customer performance | 1–5 | 1 = very poor; 5 = excellent against customer expectation. |
| Technical difficulty | 1–5 | 1 = straightforward; 5 = significant technology, cost, capability or validation challenge. |
| Roof correlation | ++ / + / − / −− | Strong positive, positive, negative or strong negative interaction. |
QFD Project Definition
Define the decision context before building the matrix0% complete
Add Customer Requirement
State the need in customer language.
Customer Requirements Register
0 requirementsAdd Technical Characteristic
Use a measurable engineering or service characteristic.
Technical Characteristics Register
0 characteristicsHouse of Quality Relationship Matrix
Enter 9, 3, 1 or blank. Priority = customer importance × relationship score.
Scoring discipline: do not force a relationship into every cell. A sparse, reasoned matrix is more useful than an artificially dense one.
Technical Priority Results
Roof Correlations
Document important positive and negative interactions.
Requirements Deployment Register
Carry priority requirements into design, process and production controls.
QFD Readiness Assessment
Score each question from 0 to 4.
Scoring: 0 = absent; 1 = major gaps; 2 = partly effective; 3 = effective with minor gaps; 4 = robust, evidenced and sustained.
Complete the assessment to obtain guidance.
Quality Function Deployment Report
Generated from the project, House of Quality and deployment records.
Complete the project and select Generate Report.