Quality Function Deployment (QFD) 121

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1 Quality Function Deployment (QFD) 121 QUALITY FUNCTION DEPLOYMENT (QFD) Once information about customer expectations has been obtained, techniques such as quality function deployment (QFD) can be used to link the voice of the customer directly to internal processes. Tactical quality planning involves developing an approach to implementing the strategic quality plan. One of the most promising developments in this area has been policy deployment. Sheridan (1993) describes policy deployment as the development of a measurement-based system as a means of planning for continuous quality improvement throughout all levels of an organization. Originally developed by the Japanese, American companies also use policy deployment because it clearly defines the long-range direction of company development, as opposed to short-term. QFD is a customer-driven process for planning products and services. It starts with the voice of the customer, which becomes the basis for setting requirements. QFD matrices, sometimes called the house of quality, are graphical displays of the result of the planning process. QFD matrices vary a great deal and may show such things as competitive targets and process priorities. The matrices are created by interdepartmental teams, thus overcoming some of the barriers which exist in functionally organized systems. QFD is also a system for design of a product or service based on customer demands, a system that moves methodically from customer requirements to specifications for the product or service. QFD involves the entire company in the design and control activity. Finally, QFD provides documentation for the decision-making process. The QFD approach involves four distinct phases (King, 1987): Organization phaseömanagement selects the product or service to be improved, the appropriate interdepartmental team, and de nes the focus of the QFD study. Descriptive phaseöthe team de nes the product or service from several different directions such as customer demands, functions, parts, reliability, cost, and so on. Breakthrough phaseöthe team selects areas for improvement and nds ways to make them better through new technology, new concepts, better reliability, cost reduction, etc., and monitors the bottleneck process. Implementation phaseöthe team de nes the new product and how it will be manufactured. QFD is implemented through the development of a series of matrices. In its simplest form QFD involves a matrix that presents customer requirements as rows and product or service features as columns. The cell, where the row and

2 122 CREATING CUSTOMER-DRIVEN ORGANIZATIONS column intersect, shows the correlation between the individual customer requirement and the product or service requirement. This matrix is sometimes called the requirement matrix. When the requirement matrix is enhanced by showing the correlation of the columns with one another, the result is called the house of quality. Figure 3.7 shows one commonly used house of quality layout. The house of quality relates, in a simple graphical format, customer requirements, product characteristics, and competitive analysis. It is crucial that this matrix be developed carefully since it becomes the basis of the entire QFD process. By using the QFD approach, the customer s demands are deployed to the final process and product requirements. One rendition of QFD, called the Macabe approach, proceeds by developing a series of four related matrices (King, 1987): product planning matrix, part deployment matrix, process planning matrix, and production planning matrix. Each matrix is related to the previous matrix as shown in Figure 3.8. Figure 3.9 shows an example of an actual QFD matrix. Figure 3.7. The house of quality.

3 Quality Function Deployment (QFD) 123 Figure 3.8. QFD methodology: Macabe approach. Data collection and review of customer expectations, needs, requirements, and specifications Another approach to QFD is based on work done by Yoji Akao. Akao (1990, pp. 7^8) presents the following 11-step plan for developing the quality plan and quality design, using QFD. 1. First, survey both the expressed and latent quality demands of consumers in your target marketplace. Then decide what kinds of things to make. 2. Study the other important characteristics of your target market and make a demanded quality function deployment chart that re ects both the demands and characteristics of that market. 3. Conduct an analysis of competing products on the market, which we call a competitive analysis. Develop a quality plan and determine the selling features (sales points).

4 124 CREATING CUSTOMER-DRIVEN ORGANIZATIONS Figure 3.9. QFD matrix for an aerospace rm. From Wahl, P.R. and Bersbach, P.L. (1991), TQM AppliedöCradle to Grave, ASQ 45th Quality Congress Transactions. Reprinted with permission.

5 The Six Sigma Process Enterprise Determine the degree of importance of each demanded quality. 5. List the quality elements and make a quality elements deployment chart. 6. Make a quality chart by combining the demanded quality deployment chart and the quality elements deployment chart. 7. Conduct an analysis of competing products to see how other companies perform in relation to each of these quality elements. 8. Analyze customer complaints. 9. Determine the most important quality elements as indicated by customer quality demands and complaints. 10. Determine the speci c design quality by studying the quality characteristics and converting them into quality elements. 11. Determine the quality assurance method and the test methods. THE SIX SIGMA PROCESS ENTERPRISE I am often asked Will Six Sigma work for... where the blank is health care, oil exploration, custom-built homes, etc. The list is unending. My typical response is that, if a process is involved, Six Sigma may be able to help you improve it. Personally, I don t believe that everything will benefit from the application of Six Sigma rigor. There are some things that aren t processes, such as pure creativity, love and unstructured play. I don t believe a chess grandmaster would benefit from the advice of a Black Belt applying DMAIC to his moves, nor would his equivalent in the R&D area. There are other things that are processes, but processes so poorly understood that we don t know enough about them to use the Six Sigma approach to improve them, such as pure research, social relationships, criminal behavior, or curing substance abuse. However, the vast majority of processes encountered in business, non-profit organizations, and government services fall into the category of processes that can be improved by the application of Six Sigma methods. But what exactly is a process? There is a tendency to narrowly interpret the term process to refer to a manufacturing operation that converts raw materials into finished products. That s true, of course. But as I use the term process throughout this book it has a much broader meaning. In this book process refers to any activity or set of activities that transform inputs to create values for stakeholders. The inputs can be labor, expertise, raw materials, products, transactions, or services that someone is willing to pay more for than they cost to create. In other words, the process adds value to the inputs. Said another way, the process is the act of creating value. The value can be a cured disease, a tasty banana split, a great movie, a successfully completed credit card transaction, or a cold soda purchased at a convenience store.

6 7M tools 265 if patients are interviewed about their hospital experience they may say the doctor was friendly, the doctor knew what she was doing, and the doctor kept me informed. Each of these statements relates to a single thing, the doctor. Many times affinity diagrams are constructed using existing data, such as memos, drawings, surveys, letters, and so on. Ideas are sometimes generated in brainstorming sessions by teams. The technique works as follows: 1. Write the ideas on small pieces of paper (Post-its TM or 3 5 cards work very well). 2. The team works in silence to arrange the ideas into separate categories. Silence is believed to help because the task involves pattern recognition and some research shows that for some people, particularly males, language processing involves the left side of the brain. Research also shows that left-brain thinking tends to be more linear, which is thought to inhibit creativity and pattern recognition. Thus, by working silently, the right brain is more involved in the task. To put an idea into a category a person simply picks up the Post-it TM and moves it. 3. The nal groupings are then reviewed and discussed by the team. Usually, the grouping of ideas helps the team to develop a coherent plan. Affinity diagrams are useful for analysis of quality problems, defect data, customer complaints, survey results, etc. They can be used in conjunction with other techniques such as cause and effect diagrams or interrelationship digraphs (see below). Figure 8.11 is an example of an affinity diagram. Tree diagrams Tree diagrams are used to break down or stratify ideas in progressively greater detail. The objective is to partition a big idea or problem into its smaller components. By doing this you will make the idea easier to understand, or the problem easier to solve. The basic idea behind this is that, at some level, a problem s solution becomes relatively easy to find. Figure 8.12 shows an example of a tree diagram. Quality improvement would progress from the right-most portion of the tree diagram to the left-most. Another common usage of tree diagrams is to show the goal or objective on the left side and the means of accomplishing the goal, to the right. Process decision program charts The process decision program chart (PDPC) is a technique designed to help prepare contingency plans. It is modeled after reliability engineering methods of failure mode, effects, and criticality analysis (FMECA) and fault tree analysis (see Chapter 16). The emphasis of PDPC is the impact of the failures (pro-

7 7M tools 267 Figure An example of a tree diagram. blems) on project schedules. Also, PDPC seeks to describe specific actions to be taken to prevent the problems from occurring in the first place, and to mitigate the impact of the problems if they do occur. An enhancement to classical PDPC is to assign subjective probabilities to the various problems and to use these to help assign priorities. Figure 8.13 shows a PDPC. Figure Process decision program chart.

8 268 PROBLEM SOLVING TOOLS Matrix diagrams A matrix diagram is constructed to analyze the correlations between two groups of ideas. Actually, quality function deployment (QFD) is an enhanced matrix diagram (see Chapter 3 for a discussion of QFD). The major advantage of constructing matrix diagrams is that it forces you to systematically analyze correlations. Matrix diagrams can be used in conjunction with decision trees. To do this, simply use the most detailed level of two decision trees as the contents of rows and columns of a matrix diagram. An example of a matrix diagram is shown in Figure Figure An example of a matrix diagram. Interrelationship digraphs Like affinity diagrams, interrelationship digraphs are designed as a means of organizing disparate ideas, usually (but not always) ideas generated in brainstorming sessions. However, while affinity diagrams seek to simply arrange related ideas into groups, interrelationship digraphs attempt to define the ways in which ideas influence one another. It is best to use both affinity diagrams and interrelationship digraphs.