Kalite fonksiyon açınımı ve akıllı telefon tasarımında uygulanması
Kali̇te fonksi̇yon açinimi ve akilli telefon tasariminda uygulanmasi
Yazar: GÖKHAN KALEM
Danışman: DR. HÜSNÜ BÜLENT CERİT
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Endüstri Mühendisliği Ana Bilim Dalı / Mühendislik Yönetimi Bilim Dalı
Derece: Yüksek Lisans, 2013
Konu: Endüstri ve Endüstri Mühendisliği = Industrial and Industrial Engineering
Dizin: Cep telefonu = Cellular phone ; Cep telefonu = Mobile phone ; Kalite = Quality ; Kalite fonksiyon yayılımı = Quality function deployment ; Kalite geliştirme teknikleri = Quality improvement techniques ; Kalite güvencesi = Quality assurance ; Telekomünikasyon = Telecommunication ; Telekomünikasyon endüstrisi = Telecommunication industry ; Telekomünikasyon sektörü = Telecommunication sector ; Toplam kalite yönetimi = Total quality management

Özet:
Yeni ürünleri hızlı ve beklentileri karşılayan bir şekilde pazara sunabilme yeteneği müşteri odaklı bütün başarılı işletmeler için günümüzde daha da önem kazanmıştır. Böylece, üretim döngülerini kısaltma, müşteri taleplerine tam karşılık verme ve pazara bu şekilde hakim olabilme amacıyla çeşitli kalite teknikleri ortaya çıkmıştır. Bunlardan biri de Kalite Fonksiyon Açınımı (KFA)?dır.
KFA, müşterinin sesini dinleyip müşteri istek ve beklentilerine göre ürünü tasarlayan bir kalite yönetim tekniğidir. KFA?da önce müşteri ihtiyaç ve talepleri belirlenir, sonra ürün veya hizmetin özelliğine göre teknik gereksinimlere karar verilir. Belirlenen müşteri talepleri ve teknik gereksinimlere göre Kalite Evi oluşturulur. Özetle, tasarım kalitesini ürün daha tasarım aşamasındayken güvence altına almanın bir yoludur.
Bu çalışmanın amacı, bir yeni ürünün müşteri beklentileri doğrultusunda tasarlanması için Kalite Fonksiyon Açınımı metodunun uygulanmasıdır. Uygulama alanı olarak Turkcell İletişim Hizmetleri A.Ş. şirketinin yeni tasarlayacağı akıllı telefon seçilmiştir.
Mobil haberleşme teknolojileri oldukça dinamik bir yapıya sahip olduğundan ürün geliştirme yöntemleri devamlı gözden geçirilip geliştirilerek rekabet avantajı sağlanmaya çalışılmalıdır. Ürün yaşam döngüsünün oldukça hızlı şekilde tamamlandığı telekomünikasyon sektörü için yeni ürün tasarımında KFA eğer vakit kaybetmeden hayata geçirilirse başarıya ulaşabilir. 
Uygulamaya geçilmeden önce sektör ve mobil telefon pazarı hakkında güncel bilgilere ve kısa tarihçeye yer verilmiştir. Geçtiğimiz yıllarda sektörel konularda yapılan KFA çalışmaları incelenmiştir. Ayrıca akıllı telefonların karakteristik özellikleri ve gelişim süreçleri anlatılarak uygulamanın daha iyi anlaşılması hedeflenmiştir. 
Uygulamanın ilk adımında proje odak grubu çalışmaları ve literatür taraması ile müşteri memnuniyet kriterleri ile teknik gereksinimler belirlenerek müşteri ve teknik kişi anketleri hazırlanmıştır. Hedef segmenti modelleyen Turkcell çalışanları arasında müşteri anketi yapılmış ve ilgili teknik gruplara da teknik kişi anketi uygulanmıştır. Sonrasında toplanan bu müşteri sesine KFA adımları uygulanarak Kalite Evi inşa edilmiştir. 
KFA yönteminin akıllı telefon tasarımına uygulanması, müşteri gereksinimlerinin gruplandırılması ve önceliklendirilmesinde Kano Modeli ile desteklenmiş ve bu sayede daha hassas sonuçlara ulaşılabilceği gösterilmiştir. Kalite Evinin sonuçlarına göre; Turkcellin müşteri odaklı yaklaşımıyla tasarlayacağı akıllı telefonun işletim sisteminde iyileştirmeye gidilmesine, kullanıcı deneyimini iyileştirecek ve daha hassas bir dokunmatik ekran sağlayacak yazılım tasarımıyla cihazın desteklenmesine karar verilmiştir. Uygulama neticesinde öncelikli müşteri gereksinimleri göz önünde bulundurularak bu sonuçlar yorumlanmıştır.

Abstract:
In recent years the capability of new product development satisfying customers in the market has been getting more important for all customer oriented companies. Therefore, various quality management techniques have arised in order to decrease product life cycle, respond to the customer demands completely and dominate the market efficiently. One of the most significant methods in this direction is the Quality Function Deployment (QFD).
QFD is a quality management technique that is listening voice of customer (VoC) and designing product as per customer demands and expectations. Firstly customer requirements are defined in the beginning of QFD process and then technical requirements are determined according to the features of product or service. After determining of customer and technical needs House of Quality (HoQ) is created. 
QFD collects customer demands through various methods and converts them into technical necessities, which allows the resources to be allocated considering customer priorities. The focal point is the customers? requirements and expectations. Products are developed considering the determined targets and priorities. Voice of customer is the start point of QFD and this stage leads all the process. Listening to customer, understanding and then interpretation of customers? needs provide with the formation of House of Quality.
QFD is a method to guarantee the quality while the product is just beginning to be designed. It discovers important points to be made powerful on design and shows the sensitive balance between customer expectations and technical features. The usage of QFD is not limited with the existing product or service. It can be utilized for the new product/service development as well. The majority of the firms have been using QFD in today?s business world, where fast responds to customer demands are gaining more importance every day. 
Mobile communication sector is one of the leading sectors based on customer focused approach which is main theme of Quality Function Deployment. Sector players try to keep on their existence by giving response to the customers? demand and requirements quickly and correctly under high competence environment. Thus, these companies need a systematic technique. In this direction QFD seems a suitable technique of total quality management because of its consideration and orientation towards voice of customer.
The aim of the study is the application of QFD method on a new product development in accordance with customer expectations. The design of new Turkcell smartphone has been selected as the application area and the case study has been explained in details of each step carried out in the company. 
In the smartphone market, it is very critical to apply quality techniques in a fast and correct way in order to meet the necessities of product/service market, since the demands are dynamic and unsteady.  This will also assure the firms to consume their resources in the right way. 
Although QFD practices have been applied to the products and services of smartphones, any specific study regarding the design of the phones haven?t been found during the literature survey. This shows the lack of QFD applications in this industry. 
QFD researches has been examined and literature scanning has been performed for the smartphone industry. However, it was not easy to find plenty of sample project for QFD in the sector due to fact that product life cycle is completed so fast. It is required to grab competitive advantage by means of continuous review of new product development techniques because mobile communication technologies are so dynamic in many respects.
In addition, updated information and short history related to the telecommunication sector and mobile phone market including smartphone have been placed before the case study section. 
The following paragraphs explains the application steps of case study and the results of the study:
At the beginning of application, customer questionnaire is arranged in order to collect the voice of customer (VoC). Target customers being included in the project are the employees from sales, marketing, vendor management, terminal test and network quality assurance departments. These persons have usage experience of T21 and T30 respectively. Distribution of questionnaire papers was handled via e-mail. 
Initially, focus group meetings were performed with the attendance of network quality assurance and terminal testing teams and then important characteristics of a smartphone were discussed amongst these technical groups. In addition, some other meetings were arranged with the team who is responsible for only T series smartphones and acquired their help. On the other hand, all the literature was surveyed deeply and conference papers and articles published in international area were taken into consideration while determining these customer satisfaction criteria.
In the foreground of these satisfaction criteria for smartphones, non-technical teams from sales, marketing and vendor management department attended in the customer questionnaire. The biggest factor affecting this choice of this questionnaire group is that these persons are positioned so close to the real customers of the firm. Additionaly, these employees use the smartphones in their daily life under test process and have opportunities of trying device features and observing its performance. Thus, it was considered that questionnaire results tend to be quite similar to the real customers? outputs due to their strong relationship and direct communication with subscribers of the firm.
In the A section of questionnaire it is wanted questionnaire group to give a score between 1 and 5 for each satisfaction criterion. Here the score ?1? means the lowest importance and ?5? means the highest importance. The level of importance is calculated from average of replies to the customer requirements. In the B section of questionnaire it is wanted the customers to evaluate the satisfaction levels of T21 and T30 smartphones for their expectations. Then after that arithmetic average is calculated from all replies. ?Improvement Ratio?, ?Absolute Weight? and ?Relative Weight? are calculated after determination of quality level and sales advantage values targetted. 
The brain storm meetings executed amongst terminal testing and network quality assurance departments enabled the determination of technical requirements that will satisfy the customer demands. Additionally, smartphones? technical specifications acquired from literature survey were included in this list. Lastly, technical features that take place in literature were examined in detail when the focus group meetings were arranged and then reduced to the following list. Thus, construction of house of quality (HoQ) and interpretation become easier. Literature survey is a significant part of this study. Especially up-to-date articles published after 2009 are taken into consideration. The reason is that technical specifications recently evolved profoundly while the mobile phone market had been passing from classical mobile phones to the smartphones.
Another questionnaire is utilized in order to measure the correlation level between customer and technical requirements as well. This study makes clear in which level each technical specification meets customer requirements. Some technical features determined by expert engineers in their areas may not be so necessary or completely necessary. This grading comes up with the correlation of two categories. Correlation matrix is formed after getting item weights of questionnaire results for the relationship between customer demands and technical requirements. Absolute and relative importance levels are calculated by using the connections between customer demands and technical requirements. 
How technical features affect each other is handled in correlation matrix under the roof of house of quality. There are lots of weak or strong positive correlations between many technical specifications of smartphones. For instance, operating system plays significant role in software design of smartphone. At the present day, updated versions of operating systems seem quite user-friendly and bring lots of functions to the customer in a simple way. Besides there is a similar correlation between processor power and software design, but correlation level can be regarded as relatively weak because processor power does not affect directly.
At the last stage of the formation of house of quality, customer satisfaction values of T21 smartphone, previous model than T30, are extracted from questionnaire results and located on the House of Quality.
The eventual purpose of QFD is high level customer satisfaction. It is assumed that each requirement for the service/product has the same influence on the customer satisfaction in this approach whereas each requirement does not have the effect in same level while meeting these requirements. In this situation, Kano Model comes up with effective approach in categorization and comprehension of the customer requirements. According to the influences of each customer requirement on customer satisfaction, different weight values are assigned. The examples from the literature survey show that the integration of Kano Model with QFD provides contribution efficiently to the high level customer satisfaction.
This categorization phase mentioned in Kano Model is carried out via applying Kano questionnaire consisting of one positive and one negative question. Kano questionnaire is arranged amongst the group who attended before to the QFD questionnaire at the beginning of the study. Then customer requirements for smartphone are categorized properly based on the replies of Kano questionnaire. This process is performed by separating them to the basic, linear and attractive requirements. 
Kano improvement parameter (k) is selected ½, 1 and 2 for the basic, linear and attractive requirements respectively. So, improvement ratio (IR) is again calculated afterwards. 
Finally, absolute importance and relative importance values are calculated in order to complete the house of quality after correction due to the Kano Model integration on the application of study. Correlation matrix, formed by the technical QFD questionnaire before, is utilized here to be able to calculate.   
According to the analyses of the House of Quality, ?Long battery life? is found to have the most weight with 13.64% relative weight raito amongst customer requirements.  ?Ease of Use? and ?Touch-operated Sceen Sensibility? follow this with 11.54% and 11.25% relative weight ratios. 
When looked at the correlation of customer requirements and technical requirements, ?Long Battery Life? is found to be possible via improvements in hardware design. Giving more space to the battery will increase its capacity. Locating the antenna at the right position will also improve battery life, since the mobile phone will lose less energy in order to communicate with the base station.  
When the first House of Quality is examined in detail, ?Operating System? is seen to have 22.65% relative importance ratio, which is the highest ratio amongst technical properties. ?Software Design? is the second with 21.42% relative importance ratio, which is followed by ?Hardware Design?, ?Processor Power?, ?the Technology of the Supported Network?,  ?Connection Support, such as Bluetooth, WiFi, NFC, A/GPS?, and ?Memory Capacity?. 
So less is changed after including the Kano Model to the application. ?Long Battery Life? and ?Ease of Use? are the first and the second ratios, with the percentages of 13.15% and 11.17%. other customer requirements are in the same order with the QFD findings. ?SMS? is in the category of the Basic Needs in Kano classification, rather than ?Internet Connection Rate? in QFD. This indicated the increase of the characteristic of SMS, which necessitates putting more effort in supplying this attribute. 
When the second House of Quality, which includes the Kano Model, is examined in detail, ?Operating System? is seen to have 22.44% relative importance ratio, which is the highest ratio amongst technical properties. ?Software Design? is the second with 21.28% relative importance ratio. Although relative importance ratios differ a little, the sequence of the basic QFD approach still stays the same.  ?The Technology of the Supported Network?,  and ?Connection Support, such as Bluetooth, WiFi, NFC, A/GPS? have higher relative importance ratios. Other technical characteristics show slight declines in their relative importance ratios. 
New smartphones will be designed according to the results of the QFD Quality Management Technique, supported by the Kano Model. The phones are suggested to have the below mentioned properties as a result of this study: 
	The usage of newer versions of Google Android operating system
	The design of a user friendly interface
	The addition of shortcuts to the main screen (like Google)
	Installing a higher capacity battery, preserving the hardware design
	Higher touch-screen sensitivity via IPS technology
	The use of a larger screen in hardware design (minimum 4 inch)
Smartphones have been analyzed from the customers? point of view, using QFD and the Kano Model, and the most important specifications have been determined. While technical necessities have been determined by QFD, the classification of the customer requirements has been made by intergration the Kano Model to the QFD study.