Customer driven design for products, services and software has become this year's buzzword. Value to the customer is the ratio of the benefits the customer receives divided by the price paid. When products are designed using customer needs, value and sales go up. When start-up problems are reduced and cycle times shortened, costs go down. Increased sales and lower costs means greater profits.
QFD translates customer requirements (voice of the customer) into design requirements (voice of the engineer). QFD has helped organizations like 3M, Ford Motor Co. and AT&T improve customer satisfaction, reduce product development time, and reduce start-up problems.
Unfortunately QFD has many formats. Some practitioners believe that QFD is the House of Quality, a matrix for mapping the voice of the customer into the voice of the engineer. Some practitioners call any matrix a House of Quality. Depth of analysis is the most significant difference in the formats. A QFD application using only the customer demanded qualities and the organizations performance measures (quality characteristics, design requirements, etc.) has very little depth. At the other extreme is comprehensive QFD, which frightens away many new practitioners. Comprehensive QFD would include at least the deployments of:
1. Quality
2. Functions
3. Reliability
4. Concepts
5. Manufacturing
6. Cost
7. Kansei
8. Gemba
9. Next Generation
Don Clausing has suggested we name a matrix by its role in the total development process. The first matrix can be referred to as the Product Planning matrix. Though this may be useful for some organization there are organization, which find the Demanded Quality vs. Function matrix the most useful first matrix.
The Major Steps
This material covers five major steps in QFD. I believe these steps form a useful set, satisfying practitioners who are interested in " blitz " QFD and comprehensive QFD. Organizations that have followed this format have been able to comfortably stop after any one of the steps and continue with their existing design process.
The first step includes activities that focus on understanding the customer. The data produced is refined, and then a subset of the information becomes the input to the second step. The prioritization of the segments is one of the outputs from Step One.
For the case of designing a tool for screw removal from bones the relevant customer segments and new customer segments could be found by looking at the intersections of three bone types, two muscle types and two fat types.
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Bones: growing bones, heavy/strong bones, or brittle bones Muscles: muscular or not muscular Fat : much fat or little fat |
This is just one way to make sure no segment is forgotten. The muscle and fat influence the length of the incision necessary to perform a traditional procedure. The analysis of the customer starts with identifying the customer segments and their characteristics. Another significant customer is the surgeon community.
Step Two involves gathering the voice of the customer and understanding the context in which the customers make statements. Contextual information clarifies the customer's verbatim information. The purpose of this activity is to establish a clear understanding of all of the customer needs, specifically the subjective performance requirements. In this manual, these subjective performance requirements are called demanded qualities. Each QFD analysis builds in some way upon these demanded qualities. Since the design is driven by customer information, the practitioner is more likely to design a product that meets or exceeds customer expectations.
The case being presented is in fact for one customer, "me." (However, but the process for customers would usually have several sources of information.) The environment in this case would, be the operating room and staff. Both the surgeon and the patient have a list of needs, and some of these are likely to be in conflict. TRIZ offers a way to be inventive without compromise. The voice-of-the-customer table contains the categories Who, What, Where, When, Why and How the product is used, will be used or can be used. From this information, a sorting process yields Demanded Qualities, Functions, Failure Modes, Solutions etc.
The demanded qualities become the foundation of a questionnaire for gathering more information about their importance and the current level of customer satisfaction with these items.
Step Three translates the customer's statements and evaluations into the design team's language for performance measures and priorities. The demanded qualities are the input to the matrix. If necessary, the design team uses demanded qualities to identify new concepts.
The design team sets priorities for demanded qualities by combining organizational priorities with the customer's priorities. They also transform the customer's subjective demanded qualities into technical performance measures, which is the output of the matrix. They use these performance measures to prioritize projects and establish desired target values for the design. These targets form the wish list that drives the design and development effort. Compromises may be required for the unattainable. This analysis is made within an expanded matrix, often called the House of Quality.
Step Four employs Stewart Pugh's system for generating new concepts. Target costs are integrated in the generation process. The output of the previous matrix analysis becomes the criterion for evaluating alternative designs. More importantly, new design concepts are generated. TRIZ offers the best way to expand the team's knowledge base. The selected new concept and associated specifications are linked to the manufacturing process and the manufacturing database.
In Step Five, the final analysis uses a matrix to link the product specifications to the manufacturing conditions. Identifying the knowledge base for the relationship between operating conditions and product performance is part of the manufacturing database. Knowing that the knowledge base for some critical operating condition is "Harry," who is 70 years old and about to retire, is significant. The output of this analysis can be control systems or procedures.
QFD does not replace an organization's existing design process. Accordingly, you can integrate QFD into a sequential, concurrent or your unique design process. For example, consider a subset of the sequential design process flow chart and the five major QFD activities. Note that you can introduce a QFD activity at various points in the design process. The approach is flexible enough that your design team can decide when to start and stop the QFD process.
Any single QFD activity will aid your understanding of the input you are using. You could merely apply QFD to the manufacturing process. You may produce a product that the customer does not want, but you will inevitably improve the manufacturing process. In general, using a middle phase of QFD will enhance your understanding, but you will gain more if you combine the activity with one or some of the earlier activities. As a rule of thumb, using any of the earlier activities is more effective than choosing one of the later phases.
You might want to check out my book Step by Step QFD: Customer Driven Product Design.