ABSTRACT A GUIDE FOR CONSTRUCTION COMPANIES TO APPLY LEAN SIX SIGMA METHODOLOGY D&Uuml / gME, Fatma Zehra M.S., Department of Civil Engineering Supervisor: Asst. Prof. Dr. Yasemin NIELSEN April 2008, 245 pages The construction sector is an immensely important industrial sector in terms of economic and social impact and also employment facilities. Nonetheless, much research has pointed out a gap in terms of labor productivity, quality, performance and responsiveness to customer needs when compared with other large industrial sectors / sectors that have recently experienced huge gains and cost reductions via methods like Lean Six Sigma. In this study, the construction industry will be examined for determination of the potential Lean Six Sigma implementation level and expected benefits from its use. The author conducted interviews with three companies in order to find out their readiness for such a management by innovation. One of the companies was selected for further study due to suitability of their organizational structure, innovative strategy and interest in this study. By taking up this pilot study and Lean Six Sigma principles as references, five roadmaps are generated as a guidance to implement Lean Six Sigma methodology for companies indicating the general steps before and during the implementation. The proposed roadmaps and applied questionnaire/interview questions developed in this thesis will also be helpful to construction companies to scrutinize their own structure and performance levels and as a guide on how to pursuit improvements through the proposed implementation of the Lean Six Sigma methodology.

The theme of the thesis is the influence of the urban development activities on the historic commercial areas. Hence, the thesis focuses on the evaluation of these factors which cause alterations and transformations within the area and aims to propose compatible solutions against the problems in order to achieve the sustainability of the historic texture within the commercial area. In this thesis, Yeni Galle Pazari Hani,, one of the 16th century Ottoman Hans in the Hanlar District of Bursa, is studied together with its immediate surrounding. In order to define necessities and requirements of a transformed historic commercial area, it is aimed to conduct research, analysis, and decision stages concerning the studied area. For this purpose, the values, the problems and the potentials of the study area are defined and alternative conservation solutions are proposed. It is also aimed to present the principles and decisions on the preservation and rehabilitation of the study area, called as &amp / #8216 / Yeni Galle Pazari Hani and its immediate surrounding&amp / #8217 / , in environmental scale. Therefore, the main aim of the thesis is to determine the principles and the tools of an urban conservation project within the context of environmental scale and to re-gain the unity of Yeni Galle Pazari Hani as much as possible by integrating it into the current atmosphere of Hanlar District in Bursa together with the traditional texture surrounding it. In this study, the insufficiency observed in preparatory stages of most of current restoration projects was emphasized. Hence, before intervention of such kind of traditional areas, it is aimed to take care of documentation, to make a comprehensive study on unobserved parts of traditional texture such as archeological excavation, and to form a worksheet containing principles and decisions for future studies that would be done under various disciplines. The proposal for the case of Yeni Galle Pazari Hani is significant as being composed of documentation, observation and decision parts of a proper intervention, although it can be accepted as an incomplete project, since being the first step of a comprehensive restoration project for the study area. In conclusion, this study exemplifies the documentation and the evaluation of the transformation in a historic commercial area and the suggestion to solve the general problems among the Historical Commercial Center of the cities by taking decisions on conservation and rehabilitation for the sustainability of the study area.

This study is about an integrated procurement and transportation planning system for purchased components of a consumer-durables manufacturer. Due to transportation cost structures and demand characteristics our problem can be classified as a variant of the dynamic-demand joint replenishment problem. The problem is to determine the replenishment policy using the advantages of coordinated transportation of items that will minimize the sum of total inventory holding and tranportation costs over a finite planning horizon. A mathematical model is formulated for purchasing and transportation decisions for the purchased items using the advantage of joint transportation costs. A two-phased solution method is proposed in order to obtain a &ldquo / good solution&rdquo / for the problem. The proposed solution method is compared with the current practice for different problem instances using retrospective data and created data. As a result it is shown that proposed method decrease the total inventory and transportation cost of the system even though the first aggregate problem can not be solved to optimality.

ABSTRACT A GENERIC RISK AND VULNERABILITY ASSESSMENT FRAMEWORK FOR INTERNATIONAL CONSTRUCTION PROJECTS &Ouml / zcan, G&uuml / lbin M.Sc., Department of Civil Engineering Supervisor: Assoc. Prof. Dr. /rem Dikmen Toker Co-Supervisor: Prof. Dr. M. Talat Birg&ouml / n&uuml / l July 2008, 105 pages Project Risk Management (PRM) comprises of identification and assessment, analysis and mitigation of risk factors in order to meet the project objectives. Risk identification and assessment process has the greatest importance as the risk models are constructed based on previously defined risk sources and their interrelations. Although previous studies have concentrated on the relation between risk events and their consequences, the link between them must be modeled by considering the various chains of risk events and the capacity of a &ldquo / system&rdquo / to react to risk events simultaneously. The concept of &ldquo / risk paths&rdquo / should be used to identify chains of risk events by means of a Hierarchical Risk Breakdown Structure (HRBS) rather than defining individual risk factors. The &ldquo / system&rdquo / consists of the characteristics of the project, company and involved parties. The word &ldquo / vulnerability&rdquo / is used to describe the degree v to which a project is susceptible to adverse effects of change. The aim of the current study is to develop a common vocabulary and design a HRBS that integrates vulnerability factors with risk factors. A generic risk and vulnerability assessment framework for international construction projects is presented in this research. The justification of the factors considered within the breakdown structure has been achieved by referring to real construction projects carried out by Turkish contractors in international markets.

Estimation of construction durations is a very crucial part of project planning, as several key decisions are based on the estimated durations. In general, construction durations are estimated by using planning and scheduling techniques such as Gannt or bar chart, the Critical Path Method (CPM), and the Program Evaluation and Review Technique (PERT). However, these techniques usually require detailed design information for estimation of activity durations and determination of the sequencing of the activities. In some cases, pre-design duration estimates may be performed by using these techniques, however, accuracy of these estimates mainly depends on the experience of the planning engineer. In this study, it is aimed to develop and compare alternative methods for conceptual duration estimation of building constructions with basic data information available at the early stages of projects. Five parametric duration estimation models are developed with the data of 17 building projects which were constructed by a contractor in United States. Regression analysis and artificial neural networks are used in the development of these five duration estimation models. A parametric cost estimation model is developed using regression analysis for cost estimations to be used in calculating the prediction performances of cost based duration estimation models. Finally, prediction performances of all parametric duration estimation models are determined and compared. The models provided reasonably accurate estimates for construction durations. The results also indicated that construction durations can be predicted accurately without making an estimate for the project cost.

This thesis investigates the key aspects of modern architecture in the first half of the twentieth century by an extensive reading of Sigfried Giedion&rsquo / s book on modern architecture: Space, Time and Architecture &ndash / The Growth of A New Tradition. Giedion&rsquo / s life, his education, his other writings and his relationships with the pioneers of the era are considered as significant influences on the writing of the book. After giving an informative summary of the book, the key themes of the book are analyzed. While analyzing these themes, the opinions of other architectural historians on these themes are also taken into consideration. The reviews on the book are elucidated in order to grasp the first reactions of architectural history circles, and then they were followed by the later impressions. The claim is that Space, Time and Architecture is an influential resource for the understanding of how modern architecture is written about in the first half of the twentieth century. The proof of this influence is both the written sources on the book and its rule in Manfredo Tafuri&rsquo / s formulation of &lsquo / operative criticism&rsquo / .

Resource constrained project scheduling problem (RCPSP) has been subject of extensive research in project management literature as RCPSP is one of the most challenging problems in the project management and is of great practical importance. In this thesis, resource allocation capabilities of Primavera Enterprise V.6.0-Project Management (P6) and MS Project 2007 (MS) were evaluated for solving overallocated problems in the RCPSP. Fourty-five resource overallocated instance projects were selected from the PSPLIB to evaluate performance of P6 and MS Project 2007. Three resource allocation priority rules of P6 and two resource allocation priority rules of MS were used for comparision. The best solutions of different priority rules for P6 and MS were compared by using t-test. Results of the P6 and MS were compared with the lower bounds and optimum solutions of the previous heuristic methods. The comparisions indicate that both P6 and MS has limited capabilities for solving overallocated problems in RCPSP. Especially for larger projects the widely used project management software packages can not provide optimum or near optimum solutions.

Information Technology (IT) is considered as a very important part of today&rsquo / s world of business and researches indicate that it helped and still helps companies to lower their costs and increase the information quality with speed. On the other hand, Senior IT Managers, such as Chief Information Officers (CIO) roles are very important in the IT department more than other department&rsquo / s relationships with their senior managers. This study investigates the identification of the effects and importance of the activities and skills of senior IT managers and their impact to the organization in the private sector. Previous studies generally studied the IS/IT Managers skills and their effects to the IS/IT department and also listed those skills and tasks. Also literature researchers focused on IS/IT managers skills, IS/IT managers effects to the IT/IS departments and IS/IT departments effects to the organization. This research study helps to highlight the importance and role of IS/IT Managers within not only private but also public sector organizations and other industries.

Project cost increase is the main concern in international construction projects which usually results in disputes and conflicts among the project participants. The aim of this thesis is to construct a database that represents risk event history regarding international construction projects and construct a cost overrun prediction model. It is hypothesized that magnitudes of project related, company related and country related risk factors can be predicted by assessing the level of vulnerability by analogical reasoning with previous projects. The vulnerability and risk factors can further be used to predict cost overrun in the bid preparation stage of international construction projects. Thus, prediction models that link vulnerability with risk factors and cost are constructed by using a dataset of 166 international construction projects, which consists of 66 real and 100 hypothetical cases. Case-based reasoning (CBR) technique is used to construct the prediction models. After testing the performance of various CBR models using different weight generation and retrieval methods, error rate of +/- 7.15 % cost increase is achieved. The utilization of CBR models in the prediction of potential risk sources and cost overrun is demonstrated by a real case study. Finally, the benefits and pitfalls of using analogical reasoning for risk and cost overrun assessment of construction projects are discussed.

This study is an attempt to examine the literary house-museums located in istanbul. In the chronological order of their transformations from houses into museums, these are Tevfik Fikret house-museum in ASiyan, Rumelihisari (1945), Sait Faik Abasiyanik house-museum in Burgazada (1964), and H&uuml / seyin Rahmi G&uuml / rpinar house-museum in Heybeliada (2000). By pointing out their ambiguous position between privacy and publicity, this research seeks to juxtapose the uses of these museums as houses in the past with the uses of these houses as museums in the present. While doing that, it aims to read their spatial stories/histories by focusing not only on the writers/inhabitants of the houses and the owners/organizers of the museums, but also on the guests/visitors of these house-museums.