What is Quality Function Deployment?
Quality Function Deployment (QFD) is a method that turns customer wants aka "Voice of Customer" into engineering plans. Its main tool, the House of Quality, connects what customers care about to how a product is designed. It helps teams focus on what matters most to buyers.
QFD Tool - House of Quality Inputs
Define relationships between customer needs and technical specifications. Changes are saved automatically.
Define correlations between technical specifications (Roof of the House). Changes are saved automatically.
| Engine Displacement (L) | Torque (Nm) | Top Speed (km/h) | Fuel Tank Capacity (L) | |
|---|---|---|---|---|
| Engine Displacement (L) | ||||
| Torque (Nm) | ||||
| Top Speed (km/h) | ||||
| Fuel Tank Capacity (L) |
House of Quality Matrix
| Engine Displacement (L) | + | ++ | |||
|---|---|---|---|---|---|
| Torque (Nm) | + | + | |||
| Top Speed (km/h) | -- | ||||
| Fuel Tank Capacity (L) | |||||
| Reliable & Durable | 5 | ● | |||
| Affordable Price | 4 | ● | ○ | ||
| Good Fuel Range | 3 | ● | ▲ | ||
| Environmentally Friendly | 4 | ● | |||
| Technical Priority | 27 | 39 | 57 | 36 | |
| Rank | 4 | 2 | 1 | 3 | |
Prioritized Technical Requirements
| Technical Requirement | Priority Score | Priority | Rank |
|---|---|---|---|
| Top Speed (km/h) | 210 | 1 | |
| Torque (Nm) | 250 | 2 | |
| Fuel Tank Capacity (L) | 55 | 3 | |
| Engine Displacement (L) | 2 | 4 |
How to Use This Tool
- Use tabs to move between sections.
- Add or remove customer needs and technical specs using the + and – buttons.
- Set relationships and correlations using dropdowns (changes save automatically).
- Click Generate House of Quality to build the matrix.
- Use Load Example for a demo or Export to Excel to save your work.
Key Components of the House of Quality
The term "House of Quality" is derived from the diagram’s distinctive architectural appearance, resembling a house with clearly defined structural elements with each serving a unique analytical function in translating customer desires into engineering specifications.
- Customer Requirements (The "WHATs"): Positioned along the left side, forming the foundational "left wall," this section captures the voice of the customer. It includes a prioritized list of expectations, preferences, and pain points identified through market research and user feedback.
- Importance to Customer: Adjacent to each customer need is a weighted score, commonly on a scale from 1 to 5. It reflects the relative significance of that need from the customer’s perspective. This helps prioritize which aspects deliver the greatest satisfaction.
- Technical Requirements (The "HOWs"): Located at the top, forming the "ceiling" of the house, these are the measurable technical parameters or design features that the development team can influence—such as performance metrics, material choices, or system configurations.
- Relationship Matrix: Occupying the central "living space" of the house, this grid maps how strongly each technical characteristic influences a given customer need. Relationships are typically coded (e.g., strong = ●, medium = ○, weak = △) to visualize which engineering decisions impact which customer expectations.
- Correlation Matrix (The "Roof"): This section, shaped like a roof, displays the correlations—positive or negative—between the technical requirements themselves. It reveals whether improving one parameter might enhance or hinder another, helping teams anticipate design trade offs.
- Technical Priorities: Situated at the base of the house, this section aggregates data from the relationships and customer weights to compute the overall strategic importance of each technical requirement. These calculated scores guide resource allocation, design focus, and performance targets, serving as the key output of the QFD process.
FAQs
Voice of Customer (VOC) refers to the process of capturing customers' requirements, expectations, preferences, and dislikes. In Quality Function Deployment (QFD), the VOC forms the foundation of the House of Quality matrix, representing the "whats" that drive product or service design.
VOC data is typically gathered through:
- Direct customer interviews and surveys
- Focus groups
- Complaint analysis
- Market research
- Product usage data
This customer input is then translated into specific, actionable customer requirements that form the left side of the House of Quality matrix.
Voice of Customer examples vary by industry but generally fall into these categories:
Product Development Examples:
- "I want my smartphone battery to last all day with heavy use"
- "The software should be intuitive enough that I don't need to read the manual"
- "The car should have comfortable seats for long drives"
Service Industry Examples:
- "I want my coffee ready within 3 minutes of ordering"
- "Customer service should resolve my issue in one call"
- "The hotel room should be completely clean upon arrival"
B2B Examples:
- "The system should integrate with our existing ERP software"
- "We need 99.9% uptime guarantee"
- "Training should be provided for our staff at no extra cost"
In QFD, these VOC statements are transformed into measurable requirements like "Battery life ≥ 12 hours" or "System integration with SAP" that can be addressed through technical specifications.
Incorporating the Voice of Customer into product development through QFD provides several significant benefits:
- Reduces development time by focusing resources on features that matter most to customers
- Decreases costly redesigns by identifying customer needs early in the process
- Increases customer satisfaction by delivering products that truly meet expectations
- Enhances competitive advantage by addressing unmet customer needs
- Improves cross-functional alignment by providing a clear customer-focused direction
Studies show that companies that effectively implement VOC processes in their development cycle experience up to 30% higher customer satisfaction rates and 25% faster time to market for new products.
While Voice of Customer (VOC) represents the needs and expectations of external customers, Voice of Business (VOB) represents the internal business requirements such as profitability, regulatory compliance, and operational efficiency.
In an effective QFD process, both VOC and VOB are considered:
| Voice of Customer (VOC) | Voice of Business (VOB) |
|---|---|
| External perspective | Internal perspective |
| Market requirements | Business constraints |
| Example: "Easy to use" | Example: "Manufacturing cost < $50" |
| Example: "Durable construction" | Example: "Complies with safety regulation XYZ" |
The House of Quality helps balance these sometimes competing voices to arrive at optimal product specifications that satisfy both customers and business needs.