Quality function deployment (qfd)
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- EXERCISES
QFD PROCESSThe QFD matrix (house of quality) is the basis for all future matrices needed for the QFD method. Although each house of quality chart now contains a large amount of information, it is still necessary to refine the technical descriptors further until an actionable level of detail is achieved. Often, more than one matrix will be needed depending on the complexity of the project. The process is accomplished by creating a new chart in which the HOWs (technical descriptors) of the previous chart become the WHATs (customer requirements) of the new chart, as shown in Figure 11–14. This process continues until each objective is refined to an actionable level. The HOW MUCH (prioritized technical descriptors) values are usually carried along to the next chart to facilitate communication. This action ensures that the target values are not lost during the QFD process. If the target values are changed, then the product is not meeting the customer requirements and not listening to the voice of the customer which defeats the purpose of QFD. An example of the complete QFD process from the beginning to the end is shown in the flow diagram in Figure 11–15. The first chart in the flow diagram is for the product-planning phase. For each of the customer requirements, a set of design requirements is determined, which, if satisfied, will result in achieving customer requirements. The next chart in the flow diagram is for part development. Design requirements from the first chart are carried to the next chart to establish part-quality characteristics. The term part-quality characteristics is applied to any elements that can aid in measuring the evolution of quality. This chart breaks down the design requirements into specific part details. Once the part-quality characteristics have been defined, key process operations can be defined in the process-planning phase. The next step is process planning where key process operations are determined from part-quality characteristics. Finally, production requirements are determined from the key process operation. 
Figure 11–14 Refinement of the QFD chart Numerous other house of quality planning charts can be used to improve quality and customer satisfaction. Some of these are the following: The demanded quality chart uses analysis of competitors to establish selling points. The quality control process chart shows the nature of measurement and corrective actions when a problem arises. The reliability deployment chart is done to ensure a product will perform as desired. Tests are done, such as failure mode and effect analysis (FMEA), to determine the failure modes for each part. The technology deployment chart searches for the advanced or, more importantly, the proper technologies for the operations. The use of these charts is dependent upon the type of product and scope of the project. 
Figure 11–15 The QFD process An example of the QFD approach can be found in the corrosion problems with Japanese cars of the 1960s and 1970s that resulted in large warranty expenses. The Toyota Rust QFD Study resulted in a virtual elimination of corrosion warranty expenses. The customer requirement of years of durability was achieved, in part, by the design requirement of no visible rust in three years. It was determined that this could be obtained by ensuring part-quality characteristics, which include a minimum paint film build and maximum surface-treatment crystal size. The key process operation that provides these part-quality characteristics consists of a three-coat process, which includes a dip tank. The production requirements are the process parameters within the key process operations, which must be controlled in order to achieve the required part-quality characteristics and customer requirements. CONCLUSIONQuality function deployment—specifically, the house of quality—is an effective management tool in which customer expectations are used to drive the design process. Some of the advantages and benefits of implementing QFD are An orderly way of obtaining information and presenting it. Shorter product development cycle. Considerably reduced start-up costs. Fewer engineering changes. Reduced chance of oversights during the design process. An environment of teamwork. Consensus decisions. Preserves everything in writing. QFD forces the entire organization to constantly be aware of the customer requirements. Every QFD chart is a result of the original customer requirements which are not lost through misinterpretation or lack of communication. Marketing benefits because specific sales points, that have been identified by the customer, can be stressed. Most importantly, implementing QFD results in a satisfied customer. EXERCISES1. Working individually or in a team, list four or more primary customer requirements for one or more of the following items. Also, refine the primary customer requirements to a second level. (a) Mountain bike (b) Racing bike (c) Pizza (d) Textbook (e) Automatic teller machine (f) Automobile cruise control (g) Coffee maker (h) Computer mouse (i) Rechargeable drill/driver (j) University academic department 2. Working individually or in a team, list six or more primary technical descriptors for one or more of the items you used in Exercise 1. Make an attempt to address all the customer requirements from Exercise 1 and refine the secondary technical descriptors to a second level. 3. Working individually or in a team, form an L-shaped matrix and complete the relationship matrix, including weights, for one or more of the items you used in Exercises 1 and 2. 4. Working individually or in a team, complete the interrelationship matrix for one or more of the items you used in Exercise 2. 5. Working individually or in a team, compare two similar products based on the customer assessment of the customer requirements you used in Exercise 1. Choose one of the products to be your organization’s product. 6. Working individually or in a team, compare two similar products based on technical assessment of the technical descriptors you used in Exercise 2. Choose one of the products to be your organization’s product. 7. Complete the scale-up column and absolute weight column for the prioritized customer requirements in Figure 11–12. 8. Complete the absolute weight row and relative weight row for the prioritized technical descriptors in Figure 11–13. 9. Working individually or in a team, complete the house of quality and comment on the results for one or more of the items you used in Exercises 1 through 6. Download 0.94 Mb. Share with your friends:
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