Ürün geliştirme ve kalite fonksiyon açınımı

Sivişoğlu, Bülent
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Fen Bilimleri Enstitüsü
Geçmişte uzman bir servisin sorumluluğunda olan kaliteyi sağlama işlevi bugün işletmenin her düzeyine yaygınlaştırılmıştır. Artık amaç, ürettikten sonra kontrol ederek kaliteyi korumaktan çıkmış; daha tasarım ve planlama aşamasında kalite yaratmaya başlama ve bunu geliştirerek sürdürme işi haline gelmiştir. Günümüz zor rekabet şartlarında bu yaklaşıma ilave edildiği zaman başarının anahtarının yüksek kalite, hız ve müşteri beklentilerini karşılayacak yeni ürün geliştirme faaliyetleri olduğu görülür. Bu amaç doğrultusunda ürünün veya servisin tasarımı ve geliştirilmesinde kullanılan tekniklerin başında "Kalite Fonksiyon Açınımı ( Quality Function Deployment )" gelir. Kalite fonksiyon açınımı ( QFD ), müşteri isteklerinin bir ürünü veya servisi tanımlayan kalite karakteristikleri, ürün fonksiyonları ve ürün alt sistemi ve parçalan olarak ürün mekanizmalarına sistematik bir yolla dönüştürülmesini sağlayan bir yaklaşımdır. QFD diğer bir deyişle müşteri taleplerinin sistematik bir yolla bir ürünü oluşturan her bir komponent, parça ve prosesin tasarım aşamasında temel olarak kullanılmasıyla ürün kalitesinin geliştirilmesidir. Bir QFD çalışması; müşteri araştırmalar ile başlar ve bu araştırmalar doğrultusunda elde edilen müşteri isteklerinin sırasıyla kalite karakteristiklerine, ürün altsistem ve parçalarına dönüştürülerek bu elemanlarla ilgili ürün geliştirme hedefi doğrultusunda, üzerinde çalışılması gerekenleri önceliklendirerek belirler ve gerek teknoloji gerekse maliyet açısından da fayda sağlayacak geliştirme faaliyetlerini tanımlar.
New Product Development and Quality Assurance With such fast-paced change occuring these days, especially in our social and economic environment, many companies are facing rapid changes in industrial structure brought about by technological innovation and changing consumer trends. These companies are finding that the effort to develop new products ic crucial for their survival. Quality function development as presented in this work provides specific methods for ensuring quality throughout each stage of the product development process, starting with design. In other words, this is a method for developing a design quality aimed at satisfying the customer and then translating the consumers' demands into design targets and major quality assurance points to be used throughout the production stage. Design review is also very important since it represents an oppurtunity to inspect the design itself. Quality function deployment is a way to assure the design quality while product is still in the design stage. Quality function deployment broadly can be defined as a system for designing product or service based on customer demands and involving all members of the producer or supplier organization. What quality function deployment does is add design to the improvement and maintenance activities of all employees to give customers the best product. Even though QFD needs to be tailored to each organization, it might be helpfull to consider QFD in four phases: 1. The Organization: During this phase management selects the product or service to be improved, the appropriate interdepartmental team and defines the focus of the QFD study. 2. The Descriptive Phase: During this phase the team defines the product or service from sevral different directions: customer demands, functions, parts, reliability, cost, etc. 3. The Breakthrough Phase: The team selects areas for improvement and finds ways to make them better through new technology, new concepts, better reliability, cost reduction, etc. and monitors the bottleneck engineering process. IX 4. The implementation Phase: The team defines the new product and how it will be manufactured. Organizing The QFD Project Management has to define the product or service to be studied. This should flow naturally from the policy management system. The initial project should focus on a product that allready exits and is well known. This makes it possible to focus on the QFD techniques. Later projects can focus on brand new product introductions. a. The extend of the study is importanat. It is possible to do a QFD study in great detail taking months and months with much research. It is also possible to do a QFD study in a matter of days and identify targets for breakthroughs and design priorities. It is possible to learn much from one chart, e.g., the so-called quality chart or house of quality which compares customer demands with quality characteristics. It is also possible to do dozens of different charts with two or three iterations of each. The extent of the study varies depending on the complexity of the product and the extent of improvement that is sought. b. Who the study is for is important. Who is requesting the study? How much funding is being provided? Who is being assigned to the team? What is the beginning and end date? QFD studies can be done by one or two people, but the effective size of the group is three to seven. What level of the organization should be involved? Who are the intended users of the study results? c. Project selection is important. Why is the project being done? What breakthroughs are required? Are new markets being sought or is the focus expansion of existing markets? Where are the breakthroughs needed? Should the focus be broad or narrow? For example, should the study be on the whole car or just the powertrain, on door or door handle? Are we talking about a new product or a product enhancement? d. Team is important. The ideal group is three to seven, an interdisciplinary group with people who have the needed expertise. The team should be people who want to be participate, if possible. Although QFD groups have been succesfully chaired by people from marketing, research and development, planning, manufacturing and quality, the largest number of groups are chaired by someone in product design. Each of the members should have a general understanding of how QFD works. The facilitator should have an in-depth understanding of QFD and the Seven New Tools. e. Statement of theme is important. It is important the theme up front. What is hoped to be accomplished? What tools will be used? How will information be shared? How will you know the project is completed? The Descriptive Phase The descriptive phase of the project defines the product from several different perspectives. These are described as follows: a. Customer Demands: A positive statement of what the customer wants and needs. It is clear enough to be understood gin the same way by most people. There are often different classes of customers whose demands are recognized. For example, in making a part for a car, you might consider the assembly plant, the dealer and the purchaser of the car, and have three groups of customer demands. b. Quality Characteristics: The items that a producer controls to assure that they meet customer demands. They state how the producer meets demands. For example, in producing large rolls of paper it has been found that a round tube is the key to no tears or creases. So the roundness of the tube is the quality characteristics for the customer demands of wrinkle free and tear free. c. Functions: Statements of what the product does. They may be like customer demands but will likely contain many key items of which only the producer is aware. d. Mechanisms: The major organizational sub-groups under the focus or the QFD study. Thay are the first level of detail. e. Parts: The next level of detail under the mechanisms. They are the second level of detail of the study. It is sometimes difficult to understand the use of the categories, mechanisms and parts as they apply to a QFD study because they are used differently in different studies. It is possible to do a QFD study on a whole car, a major part of a car or a small component. In each of these studies the concept of mechanisms and car are used differently. f. New Technologies: New materials that go into a product, new breakthroughs in engineering. Ideas for new technology come from trade journals, engineering schools and company central engineering or research and development groups. g. New Concepts: New ways of thinking about the product or its parts. h. Product Failure Modes: Ways in which the product as a whole can fail, i. Parts Failure Modes: Ways in which individual parts can fail. XI The Breakthrough Phase Creativity can be describee as combining two items in a new way for benefit. QFD uses the matrix s/stem to do this. These matrices are made by combining the various categories from stage two. Looking at several of the matrices at once you get a matrix of matrices The Implementation Phase An informal survey of companies indicates that no two companies design products the same way. In fact many claim that in the same company no two products are designed the same way. This fluidity may account for some of the waste of time and resources in design. Certainly it makes the job of looking at the design process more difficult. Hopefully the following outline will be at once general and also specific enaugh for each company or service organization to relate to it. In general, the development of new products may be traced in the following steps: Product planning, Product design, Product preparation, Regular production, Sales and service, Comprehensive monitoring Product planning has to do ith deciding what business you are going to be in. It has to do with idetttifying existing needs and evaluating the extent to which the company or any of its competitors are meeting those needs. The workload for product planning is divided into surveying, general product planning and individual planning. Surveying Surveying includes gathering information about product class. The sales department is responsible for determining market requirements. Design engineering is responsible for surveying competing products and surveying patent rights. Manufacturing engineering is responsible for testing competing products. Quality assurance is reponsible for doing a preparatory study of quality requirements. All of this is overseen by a project director. This information is analyzed in the initial quality table and the matrix data analysis. General Poduct Panning The analysis of the Mtrix Data Analysis leads to an understanding of market segmentation, where a product sits in comparison to the competition and, most importantly, which product opportunities exist. These product opportunities may include the expansion of product in existing markets or new markets or the introduction of new products in existing markets or new markets. Individual Product Planning The individual product planning is greatly expended in QFD by better defining the product. Qfd has many tools to help improve this stage. There are five sections to product definition. These include establishing: the quality plan the cost plan the technology plan the reliability plan the new concept plan Each of these plans has four parts: the customers' demands the product function quality characteristics parts Each of these has a specific matrix chart and all the charts taken together are called matrix of matrices. Product Design During the product design phase there are three stages: Design development, prototype, and testing and evaluation. Design Development This stage is the development or the product and the manufacturing process. The quality tables are redone based on the results of the last design review and the manufacturing deployment charts are developed. Manufacturing After beginning manufacturing, only small things change. All major changes are kept for the next model.
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1995
Anahtar kelimeler
Kalite güvence sistemi, Kalite kontrol, Kullanıcı gereksinimleri, Ürünler, Quality assurance system, Quality control, User requirements, Products