QFD offers several benefits to organizations.
It uses a planning matrix to define the relationship between customer requirements and the capability of the product and the company to satisfy these requirements. Because this matrix looks like a house, where customer requirements and product attributes resemble the main living quarters, competitive analysis resembles the porch, and the correlation matrix resembles the roof, it is called House of Quality.
It starts with customer requirements. The customers for a product or service are identified and their requirements from the product or service are gathered using different tools such as focus groups, surveys, and customer experiences. A structured list of customer requirements is then drawn by analyzing and organizing this data using tools such as affinity diagrams and tree diagrams.
Importance ratings are used for quantify the customer requirements and rated according to their importance on a scale of 1 to 5. This rating will be used in the relationship matrix at a later stage.
Another element is the Competitive analysis where customers views about the competition are gathered through research to provide a better understanding of the market. Here, the customers rate an organization’s products or services against competitors’ products or services. Also, Technical requirements that are not known to customers are identified and documented. These requirements generally stem from management or regulatory standards that a product must meet.
Relationship matrix defines the relationship between customer requirements and an organization’s ability to meet those requirements is determined. The relationship between the two factors is classified as weak, moderate, or strong and given the values of 1, 3, and 9, respectively. Even, in Importance weighting rating, Customer requirements are weighted according to their importance for defining and prioritizing key criteria. The relative importance of customer needs and the company’s and competitor’s performance are taken into account while calculating this. Target values for each product or service attributes, known as technical descriptors, that can be used as benchmarks against competitors’ target values are established. These target values are the “how much” of these product or service attributes.
The technical descriptors are compared with the competitors’ technical descriptors using scientific analytical techniques to assess their properties is called Engineering analysis. This also includes reverse engineering competitors’ products or services to determine the values for their technical descriptors. Correlation matrix is the relationship among customer requirements are analyzed to identify correlated requirements. The relationships are then ranked for determining areas of improvement that need to be focused upon.
The voice of the customer (VOC) is gathered and converted into technical requirements in this phase. A business case is then established and a project charter is prepared along with milestones. A team is also formed to carry out the project. Roles and responsibilities of the team members are also set during this phase. These activities are accomplished using tools such as Quality Function Deployment (QFD); Failure Modes and Effects Analysis (FMEA); the Suppliers, Inputs, Process, Outputs, and Customers (SIPOC) diagram; the Integrated Product Delivery System (IDPS); target costing; and benchmarking.
In this phase, the concept design is developed by formulating alternative concepts and choosing the best concept after evaluating the alternatives. Risks associated with the chosen concept design are also determined. The functional requirements and their Critical to Quality (CTQ) attributes are identified by the Six Sigma team. The CTQ attributes are deployed after assessing their effect on functional requirements. Raw materials and their procurement plan with the related manufacturing plan are created during this phase. In addition, the Sigma capability is predicted. These activities are accomplished using tools such as smart simple design, risk assessment, FMEA, engineering analysis, materials selection software, simulation, DOE, systems engineering, and the capability of the process is evaluated to verify if the CTQs can be met.
The design is optimized for reliability and performance by developing detailed design elements. This helps optimize the Sigma capability and cost. These activities are accomplished through manufacturing database and flowback tools, a design for manufacturability, process capability models, a robust design, Monte Carlo methods, tolerancing, and Six Sigma tools.
The prototype is tested using formal tools to validate the design. After evaluating the performance, failure modes, and risks of the design, new requirements to be met are sent to manufacturing and sourcing units. The design is iterated until it meets the requirements of the customer. A final phase review to assess the reliability is also carried out to validate the design. The term Verify is also used interchangeably for this phase. These activities are accomplished through accelerated testing, reliability engineering, FMEA, and disciplined New Product Introduction (NPI).