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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Risk analysis in management planning and project control : probabilistic techniques are applied to the estimation, planning, forecasting and control of large capital projects to ascertain and reduce the degree of inherent risk and uncertainty

Ashrafi, Rafi M. January 1981 (has links)
Effective estimation, planning, and control of the functions, operations, and resources of a project are among the most challenging tasks faced by the management of today's engineering and construction organisations. The increase in size and complexity of modern projects demand a sound organisational structure and a rational approach. The main objectives of the present study are two-fold. Firstly to report and critically review theoretical and practical developments of different aspects of the management of engineering and construction projects. Secondly to further develop conceptual, practical techniques and processes; also to provide Guidelines to make more effective use. of resources and systems. To achieve these objectives the present research was carried out in close collaboration with various indurtrial organisations. The current literature on project management is critically examined from the point of View of project cost estimation, planning and control. Various existing and recommended procedures, approaches and techniques are reviewed with particular emphasis on using probabilistic techniques. As the problems of scale are increasing, progressively more industries are adopting systems and project management approaches. Problems, deficiencies and gaps in the existing systems are identified. An analysis of a questionnaire survey on Systems-Caps is carried out and the results of the analysis are reported. . S-curves (or progress curves) are widely used in the plauaing and control of cost, time and resources. A mathematical model for the S-curve is adopted for this purpose. Expenditure data on a number of ii recent projects is analysed and fitted to two S-curve models suggested by Keller-Singh and the Department of Health and Social Security (D. H. S. S. ). A comparative study of the models is carried out. A set of standard parameters for the models is obtained and the predicting accuracy of these models for forecasting expenditure for future similar projects investigated. Quantification aspects of risk involved with the completion time of a project are studied. 'A number of stochastic distributions arc fitted for this purpose to the programed and actual durations for the different activities of a housing project. The maximum likelihood method is used for the estimation of parameters of the fitted distributions. Due to the increasing use of indices in the construction industry, building cost and tender price indices, their application, limitations and methods of formation are discussed. Box-Jenkins models are employed to study past behaviour and to forecast future trends for labour, materials and building cost indices. Finally, general conclusions derived from the present regearch are sunmarised and areas requiring further research are proposed.
42

A content based approach for investigating the role and use of email in engineering design projects

Wasiak, James Oliver January 2010 (has links)
The use of email as a communication and information sharing medium in large, complex, globally distributed engineering projects is widespread; yet there exists little understanding of the content of the emails exchanged and the implications of this content on the design project, design records and contracts. The importance of these issues is underlined by the fact that email records can now be required as evidence in legal disputes. It follows that the overall aim of this research is to assess the role and use of email in engineering design projects. A state-of-the-art review of literature pertaining to email is reported, along with a review of information and communication processes in engineering design projects. The primary contribution of this thesis is the creation of a content based approach for analysing the role and use of email in engineering design projects. This centres on the development and application of a coding scheme to email text, identifying what subject matter an email relates to, why it was sent, and how its content is expressed. Results are then analysed with respect to the frequencies of each code and other variables, including how coding varies between different senders and throughout the project duration. The second key contribution of this thesis is the analysis of emails and content in an engineering setting by applying the aforementioned approach to two case studies. The major case study concerned a large, complex, globally distributed, multimillion pound systems engineering project, from which 16 000 emails were obtained. It was found that emails are mainly used to transfer information but also to support management functions. Emails facilitate design work but little of this takes place explicitly in the email content. Characteristics of a project affect the subject matter or emails but have little effect on why they are sent. User roles and personal preferences also influence email use. If was found that the purposes for sending emails varied over the duration of a project; it was further determined that these changes could be used to identify project progress and design activity. Implications of the findings are identified in relation to: information management, knowledge management, project management, collaboration and email practice. Significantly, emails do contain potentially important design information and because these often support decisions made elsewhere, emails should be integrated with wider records. More consideration and training should be given to the use of project standards for email use and guidelines for composition. Changes in email use over the project duration could be a potential tool for project managers to identify design progress and possible issues in a project.
43

Industrial development in a high tech sector of a developing country : the unfinished technological transition in the Brazilian vaccine industry

Zuma Medeiros, Mauricio January 2011 (has links)
This thesis investigates the development of the Brazilian vaccine industry. This industry has experienced a sharp growth in the last decades supported by public policies and a protected and fast-growing public market. In addition, this development is apparently characterized by continuous processes of technology acquisition, rather than indigenous R&D, as the main source of its technological knowledge, and by other specificities in the vaccine context. The research draws on studies of the dynamics of technological capability building in catching-up industries of latecomer contexts, especially during the transition period when they are approaching the innovation frontier. It also draws on those studies focusing on new directions/paths as an alternative strategy adopted to overcome barriers and disadvantages to develop. It has been argued that the specificities of the Brazilian context and, of the vaccine sector, may be determining a particular pattern of technological accumulation to this industry, and that interpreting its pattern of development may be useful to understand how and if this industry has overcome its constraints to develop. A framework based on linear approaches of catching-up, and that integrates the innovation transition approach was built as a benchmark model for the search for similarities and differences in the pattern of development of this industry. The findings show similarities and new directions in the process of technological accumulation of the industry, suggesting that, more recently, it has actually developed through a distinct pattern. They also show the strong role of the government and its public market as one of the drivers of this new path. Distinct roles of the technology acquisition strategy and a high level of technological capabilities currently developed are also revealed. Finally, they show that the technology acquisition strategy has effectively contributed to the development of this industry and that the constraints to the completion of the transition phase is linked less to technical and scientific issues and more to managerial and policy ones.
44

Validation Of Methods Time Measurement Data

Bahcivancilar, Ugur 01 September 2012 (has links) (PDF)
This thesis shows the results of an experiment in order to test the validity of Methods Time Measurement (MTM) data. MTM, developed in 1948, is one of the most commonly used Predetermined Motion Time Systems to calculate standard time for a task. However, there is limited research on the validity of the MTM data in the literature. Today&rsquo / s technology provides new computerized tools to perform time studies. One of such tools is Real Time Method Study (RTMS). RTMS is a computerized method study tool being developed in METU Technopolis, which uses Image Processing and Machine Learning to conduct time studies automatically. RTMS uses MTM data as a benchmark data to compare observed performance results / therefore validity of MTM data is an important issue for it. In order to test the validity of MTM data an experiment conducted in the Ergonomics Laboratory of the METU Industrial Engineering Department. In this experiment 40 undergraduate students performed four different tasks. These tasks were recorded by a video camera and analyzed frame by frame to calculate normal times for basic motions of MTM. Results are compared with the original MTM data and it is shown that MTM times do not fit the observed data. This study in the end suggests updating MTM data or constructing a new standard time database by using a tool like RTMS.
45

Modeling And Analysis Of The Facility Layout Problem

Kirkizoglu, Zeynep 01 July 2006 (has links) (PDF)
The facilities layout problem, which is an integral part of facilities design, aims to spatially locate the production units within a facility subject to some design criteria and area limitations, with one or multiple objectives. In this study, the layout problem is reviewed in detail, with an emphasis on the dynamic environment it operates in. Despite the fact that layouts within the context of changing manufacturing requirements represent the problem better, the single period block layout problem is observed to have remained worth analyzing. In this thesis, a hybrid model that combines the strong aspects of the available models in the literature is constructed for the single period block layout problem. The LP relaxation of this model and the effect of adding valid inequalities to the model are studied. A rounding heuristic based on the LP relaxation of the problem is proposed and computational experimentation is made. Also, an evolutionary algorithm scheme that uses the sequence pair representation is proposed. Three mutation operators are developed to be used in this scheme. Preliminary test are made for implementations of these operators and results are given.
46

A Dea-based Approach To Ranking Multi-criteria Alternatives

Tuncer, Ceren 01 August 2006 (has links) (PDF)
ABSTRACT A DEA-BASED APPROACH TO RANKING MULTI-CRITERIA ALTERNATIVES Tuncer, Ceren M.Sc., Department of Industrial Engineering Supervisor: Prof. Dr. Murat K&ouml / ksalan August 2006, 88 pages This thesis addresses the problem of ranking multi-criteria alternatives. A Data Envelopment Analysis (DEA)-based approach, the Method of the Area of the Efficiency Score Graph (AES) is proposed. Rather than assessing the alternatives with respect to the fixed original alternative set as done in the existing DEA-based ranking methods, AES considers the change in the efficiency scores of the alternatives while reducing the size of the alternative set. Producing a final score for each alternative that accounts for the progress of its efficiency score, AES favors alternatives that manage to improve quickly and maintain high levels of efficiency. The preferences of the Decision Maker (DM) are incorporated into the analysis in the form of weight restrictions. The utilization of the AES scores of the alternatives in an incremental clustering algorithm is also proposed. The AES Method is applied to rank MBA programs worldwide, sorting of the programs is also performed using their AES scores. Results are compared to another DEA-based ranking method. Keywords: Ranking, data envelopment analysis, weight restrictions.
47

A Decision Matrix Based Method For Determining Priorities Of Quality Improvement Projects In Manufacturing With Inspection Error And Rework

Dolgun, Leman Esra 01 December 2006 (has links) (PDF)
Today&rsquo / s competitive environments and heightened expectation of customers make it necessary to improve quality of products and processes continuously. Therefore, quality improvement is a major concern for companies. Determining improvement priorities for not only long but also short term bottom line results is a key problem in quality improvement management. In this thesis a practical decision matrix based method is developed for selecting quality improvement projects by considering throughput and quality loss in manufacturing environments with inspection error and rework. Performance of the proposed method under different experimental conditions is analyzed and results are discussed.
48

A Case Study: Improvement Of Component Placement Sequence Of A Turret Style Smt Machine

Cengel, Savas Mehmet 01 January 2007 (has links) (PDF)
This study aims to improve component placement sequencing of a number of PCBs produced on a turret style SMT machine. After modeling the problem and having found that an optimal solution to the real PCB problem is hard to be achieved because of the concurrent behavior of the machine and the PCB design parameters, two heuristics are developed by oversimplifying the problem down to TSP. Performance of the heuristics and the lower bounds is evaluated by comparing the results with the optimal solution for two sets of randomly generated PCBs. The heuristic solutions are also compared with the lower bounds and the current implementation for the real PCBs. It is found out that the heuristics improve the current efficiency figures of the company.
49

Demand Driven Disassembly Planning

Ertem, 01 January 2007 (has links) (PDF)
In this thesis, we deal with the demand driven disassembly planning. The main aim of the study is to construct heuristic approaches according to the suggested improvements in the literature. These heuristic approaches are further improved by recognizing the key points of the disassembly planning problem. All of the solution approaches aim minimizing total cost related to relevant costs of disassembly operations. Another subject given attention in this thesis is the importance of the setup cost on the disassembly planning, which has not been studied yet in the literature to the best of our knowledge. Computational studies are carried out to assess the performance of the heuristic procedures proposed.
50

Alternative Mathematical Models For Revenue Management Problems

Terciyanli, Erman 01 July 2009 (has links) (PDF)
In this study, the seat inventory control problem is considered for airline networks from the perspective of a risk-averse decision maker. In the revenue management literature, it is generally assumed that the decision makers are risk-neutral. Therefore, the expected revenue is maximized without taking the variability or any other risk factor into account. On the other hand, risk-sensitive approach provides us with more information about the behavior of the revenue. The risk measure we consider in this study is the probability that revenue is less than a predetermined threshold level. In the risk-neutral cases, while the expected revenue is maximized, the probability of revenue being less than such a predetermined level might be high. We propose three mathematical models to incorporate the risk measure under consideration. The optimal allocations obtained by these models are numerically evaluated in simulation studies for example problems. Expected revenue, coefficient of variation, load factor and probability of the poor performance are the performance measures in the simulation studies. According to the results of these simulations, it shown that the proposed models can decrease the variability of the revenue considerably. In other words, the probability of revenue being less than the threshold level is decreased. Moreover, expected revenue can be increased in some scenarios by using the proposed models. The approach considered in this thesis is especially proposed for small scale airlines because risk of obtaining revenue less than the threshold level is more for this type of airlines as compared to large scale airlines.

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