Evaluating quality in mass-housing projects via six sigma: The case of Odtükent

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mimarlık Fakültesi, Mimarlık Bölümü, Türkiye

Tezin Onay Tarihi: 2006

Öğrenci: FATİME FERYAL ÇELİKNALÇA

Danışman: SOOFİA TAHİRA ELİAS ÖZKAN

Özet:

Quality and quality management have gained importance in the construction industry also due to losses of life and property. For high-quality buildings, the amount of defects during the construction works must be reduced. Thus, it is important to determine the defects which lead to low quality in the construction projects; and architectural, structural and constructional standards to measure some indicators of quality like workmanship, design of components and usage of correct and highquality materials. Therefore a systematic approach is required to achieve good standards both in design and construction. CONQUAS quality assessment system and Six Sigma quality management system are systems that could provide this systematic approach. The objective of this research is to evaluate the quality in mass-housing projects via Six Sigma. Thus, level of construction quality of the three houses in ODTÜKENT housing units in Turkey were assessed through Six Sigma with the contribution of CONQUAS quality assessment system. CONQUAS was used for determination of standards, whilst Six Sigma was used for data analysis. After the evaluation of interviews with contractor, site-supervisor, occupants and visual observations, defects and their reasons were determined. Reasons of poor quality in ODTÜKENT housing units were listed as firstly poor workmanship, then improper or of poorquality material usage and lastly problems in design of detailing. Despite different construction dates of units studied, the results show that nothing was learned from the previous mistakes and same defects were repeated. This shows the importance of a system providing feedback and evaluation of quality level of a construction project and quality improvement efforts of the contractor, and measuring the progress over time like Six Sigma.