The design of traffic signal control plan is directly related to the level of traffic congestion experienced both at the junction level and the network particularly in urban areas. Ensuring signals are well designed is one of the most cost-effective ways of tackling urban congestion problems. Signal time plans are designed with the help of signal optimization models. Optimization can either be done for multiple or single objectives and is formulated as a problem of finding the appropriate cycle lengths, green splits, and offsets. Some of these objective functions include; better mobility, efficient energy use, and environmental sustainability. LinSig and TRANSYT are two of the most widely used traffic signal optimization tools in Sweden. Each of them has an inbuilt optimization function which differs from the other. LinSig optimizes based on delay or maximum reserve capacity while TRANSYT optimization is based on performance index (P.I) involving delay, progression, stops and fuel consumption.This thesis compared these optimization models through theoretical review and application to a case study in Norrköping. The theoretical review showed that both TRANSYT and LinSig have objective functions based on delay and its derivatives. The review also showed that these models suffer from the inability to accurately model block back as they are based on the assumption of vertical queuing of traffic at the stop line. Apart from these similarities, these two models also have significant variations with respect to modeling short congested sections of the network as well as modeling mixed traffic including different vehicle classes, pedestrians, and cyclists.From the case study, TRANSYT showed longer cycle time compared to LinSig in both scenarios as its optimization objectives include both delay and stops while LinSig accounts for only delay. The Allocation of phase green splits and individual junction delay was comparable for undersaturated junctions while congested network sections had significant differences. Total network delay was, however, less in LinSig compared to TRANSYT. This could be attributed to different modeling criteria for mixed traffic and congested network in addition to the fact that cyclists were not modeled in TRANSYT. VISSIM simulation of the two-signal time plans showed that network delay and queue lengths from TRANSYT signal timings are much less compared to LinSig time plans. A strong indication of better signal coordination.

Photolithography is the most complex of the operations involved in the fabrication of a wafer, and it requires the greatest precision. Photolithography is used to create multiple layers of circuit patterns on a chip. Traditionally, wafer fab operations, and in particular, those performed in the photolithography processing area, have always presented challenging scheduling and control problems. Some of the characteristics that make the photolithography processing area difficult to schedule are as follows: reentrant flow, unpredictable yield and rework time at critical operations, shared resources such as reticles, rapidly changing technologies, and lot dedication for steppers and scanners for critical layers. This processing area, where wafers are exposed using scanners or steppers, typically, comprises the bottleneck workstations. Also, the numbers of reticles available for a given layer of product type are limited. Consequently, it is important to develop appropriate schedules to ensure effective utilization of the tools involved. In this study, a manufacturing line that is used to produce four dynamic random access memory (DRAM) products, requiring approximately 240 stages with 18 photolithography layers, is considered. The problem we propose to investigate can concisely be described as follows: Given a set of products to be processed in a photolithography area consisting of steppers and scanners (tools), with each product requiring a specific reticle type, determine the sequence in which to process the lots on the tools loaded with requisite reticles, so as to minimize the cycle time. The reticles required for processing a product are known apriori and can be transferred from one tool to another. Also, the lot dedication requirement has to be met. This requirement pertains to the fact that some of the layers of a lot should be processed on the same tool. (Scanner or Stepper). The processing of other layers may not require lot dedication. These are handled accordingly. Some lots may enter into the system with the requirement of processing them urgently. (called hot lots). These are handled in the formulation of the problem as such. Two solution methodologies are presented for the above stated problem. The first methodology uses a mathematical programming based approach. For the given routes and processing times of the product types, the entire problem is formulated as an Integer program. This integer program uses the start time of the jobs at various operations and the availability of reticles as variables, among others. The objective is to reduce the cycle time of the lots released into the system. The cycle time of a lot is defined as the time that a lot spends in the system. Results from the experimentation for integer program show that the computation time for solving small size problems is very high. A methodology is presented to solve this model efficiently. The second methodology consists of the development of a new dispatching rule for scheduling lots in the photolithography processing area. This along with the other dispatching rules discussed in the literature are implemented using the Autosched AP software to study the impact that lot dedication makes on the performance of a fab. The performance measures that are considered include throughput, cycle time, WIP and utilization of tool sets. The results are presented for 1-level, 2-level and 3-level lot dedication schemes. . It is shown that the 3- level lot dedication scheme performs the best under no preventive maintenance/breakdown case while, for the deterministic value of unscheduled breakdown times and preventive maintenance schedule used, 1-level lot dedication performed the best. Even though the 3-level lot dedication scheme is more flexible as compared to the 1–level lot dedication scheme, yet for the values of unscheduled breakdown times and preventive maintenance schedule used, the performance of the 3- level lot dedication scheme is worse than that of the 1- level lot dedication scheme. For another set of break down time values and preventive maintenance schedule, the outcome can be different. We also compare the performance of the proposed procedure with that of the dispatching rules available with the AutoSched AP software. The results indicate that the proposed procedure is consistent in generating better solutions under different operating conditions. / Master of Science

The semiconductor industry provides a host of very challenging problems in production planning and scheduling because of the unique features of the wafer fab. This research addresses the need to develop an approach, which can be used to generate optimal or near-optimal solutions to the scheduling problem of a wafer fab, by using Mathematical Programming for a general case of a wafer fab. The problem is approached in two steps. First, the number of lots of different products to be released into the system during each planning period is determined, such that the total tardiness of the product orders is minimized over the planning horizon. Second, the schedule of these lots is determined so that the cycle time of each lot released into the system is minimized. Thus, the performance measures based both on due dates and cycle time are considered. The lot release, tardiness problem is formulated as an integer linear program, and a 3-phase procedure, which utilizes a variation of the Wilkerson-Irwin algorithm, is developed. The performance of this 3-phase procedure is further improved by using insights from classical scheduling theory. The scheduling problem is formulated as a 0-1 integer linear program. An algorithm is developed for tightening the LP relaxation of this 0-1 integer linear programming model (of the scheduling problem) leading to a better performance of the branch and bound procedure used for its solution. Lagrangian relaxation is applied on a carefully chosen set of constraints in the scheduling problem, and a Lagrangian heuristic is developed for scheduling the jobs in each period of the planning horizon. Several useful insights are developed throughout to further improve the performance of the proposed algorithm. Experiments are conducted for both the tardiness and the scheduling problems. Five experiments are conducted for the tardiness problem. Each experiment has a different combination of number of products, machines, and work orders in a small sized wafer fab (2 to 6 products, 8 to 10 station families, 15 to 30 workstations, 9 to19 work orders, and 100 to 250 lots per work order). The solutions obtained by the 3-phase procedure are compared to the optimal solutions of the corresponding tardiness problems, and the tardiness per work order for the 3-phase procedure is 0% to 25% greater than the optimal solution. But the time required to obtain the optimal solution is 22 to 1074 times greater than the time required to obtain the solution through the 3-phase procedure. Thus, the 3-phase procedure can generate almost optimal solutions and requires much smaller computation time than that required by the optimal solution. Four experiments are conducted to test the performance of the scheduling problem. Each experiment has a different combination of number of products, machines, routes, bottleneck stations, processing times, and product mix entering the system each day in a small sized wafer fab (2 products, 8 station families, 18 workstations, and 8 to 10 lots released per day into the system). The solution quality of the schedule generated by the Lagrangian heuristic is compared to the solution provided by the standard dispatching rules available in practice. In each experiment, the cycle time of a product for each dispatching rule is divided by the best cycle time for that product over all the dispatching rules in that experiment. This ratio for the Lagrangian heuristic in each experiment and over all the experiments varies from 100% to 104%. For the standard dispatching rules, this ratio ranges from 100% to 120% in each experiment and also over all the experiments. The average of the ratio over all the experiments is the least for the Lagrangian heuristic. This indicates that for the experiments conducted, the Lagrangian heuristic consistently provides a solution that is, or is close to, the best solution and, hence, quite competitive when compared to the standard dispatching rules. / Master of Science

<p> </p><p> </p><p><strong>Purpose</strong> - The purpose of the thesis is to record the content of the information shared by buyer to supplier in independent dyadic business relationships in the clothes manufacturing industry of Imbaba and Warrak, Great Cairo, Egypt. The objective is as well to describe how this sharing is managed in terms of communication frequency, order cycle time and information technology used.</p><p><strong>Methodology</strong> – A case study was performed on four companies in the clothes manufacturing industry of Imbaba and Warrak, Egypt. The empirical data was collected through six semi-structured interviews. The results were thereafter analyzed through a summarized framework.</p><p><strong>Findings</strong> - The content of shared information is mainly of traditional character, nevertheless do 50 % of the relationships as well include elements of additional soft information. When the information sharing is performed through regular communication do the frequency vary with an average of 0.43, once every 2.3 days. The order cycle times vary from delivery the same day as order placement to three days after order placement, with an average of 0.5 days. The information is shared through two different information technologies: face-to-face and telephone.</p><p><strong>Research implications</strong> – Imbaba and Warrak are considered one of the poorest districts in the Great Cairo region. The region has although seen great development the last 12-15 years and is today a main district for the industry of clothes manufacturing in Cairo. The role of information sharing yet appears to be poorly examined.</p><p><strong>Originality/value</strong> - Making the situation evident to the case companies will impact on their possibilities to make further improvements within the area of information sharing.</p><p><strong>Key words</strong> Information sharing, dependence, independence, dyad, content, frequency, order cycle time, information technologies.</p><p><strong>Paper type</strong> Bachelor Thesis</p><p> </p>

Mathematical models, that depict the dynamics of a cancer cell population growing out of the human body (in vitro) in unconstrained microenvironment conditions, are considered in this thesis. Cancer cells in vitro grow and divide much faster than cancer cells in the human body, therefore, the effects of various cancer treatments applied to them can be identified much faster. These cell populations, when not exposed to any cancer treatment, exhibit exponential growth that we refer to as the balanced exponential growth (BEG) state. This observation has led to several effective methods of estimating parameters that thereafter are not required to be determined experimentally. We present derivation of the age-structured model and its theoretical analysis of the existence of the solution. Furthermore, we have obtained the condition for BEG existence using the Perron-Frobenius theorem. A mathematical description of the cell-cycle control is shown for one-compartment and two-compartment populations, where a compartment refers to a cell population consisting of cells that exhibit similar kinetic properties. We have incorporated into our mathematical model the required growing/aging times in each phase of the cell cycle for the biological viability. Moreover, we have derived analytical formulae for vital parameters in cancer research, such as population doubling time, the average cell-cycle age, and the average removal age from all phases, which we argue is the average cell-cycle time of the population. An estimate of the average cell-cycle time is of a particular interest for biologists and clinicians, and for patient survival prognoses as it is considered that short cell-cycle times correlate with poor survival prognoses for patients. Applications of our mathematical model to experimental data have been shown. First, we have derived algebraic expressions to determine the population doubling time from single experimental observation as an alternative to empirically constructed growth curve. This result is applicable to various types of cancer cell lines. One option to extend this model would be to derive the cell cycle time from a single experimental measurement. Second, we have applied our mathematical model to interpret and derive dynamic-depicting parameters of five melanoma cell lines exposed to radiotherapy. The mathematical result suggests there are shortcomings in the experimental methods and provides an insight into the cancer cell population dynamics during post radiotherapy. Finally, a mathematical model depicting a theoretical cancer cell population that comprises two sub-populations with different kinetic properties is presented to describe the transition of a primary culture to a cell line cell population.

A realização de projetos dentro do prazo estabelecido é um fator comum em diversas áreas de produção como a engenharia civil, de aviação, química, transportes, indústria em geral, entre outras. No entanto, na engenharia de software, a questão do tempo na construção de um produto é um desafio de processo a ser superado em cada novo projeto. O cumprimento de prazos no desenvolvimento de software é tão crítico que o próprio controle de atrasos no ciclo de produção é um fator a ser considerado na análise de redução do tempo de desenvolvimento. A complexidade do ambiente de software, a competitividade de mercado, as mudanças de requisitos constantes durante o projeto e o tempo disponível cada vez mais restrito, aumentam as chances de insucesso quando analisado o indicador de tempo na produção de software. O objetivo deste trabalho é reunir e organizar as práticas e técnicas de engenharia de software em um roteiro que permita a redução do tempo no desenvolvimento do software. Neste roteiro, é descrita a utilização organizada e planejada das práticas de engenharia de software que auxiliam no planejamento, na criação da arquitetura de solução, na definição da infra-estrutura técnica para reutilização e a utilização da engenharia simultânea, visando proporcionar ganhos reais no tempo de produção do software e no aumento da produtividade. / The completion of software project within schedule is a common goal in several industries like building engineering, aviation, chemical, transport, wares and so on. However, in software engineering, the schedule is a process challenge from the beginning of each new project. The time is so critical that the delay control is an analysis point for cycle time reduction in software development. The complex environment, the pressure to reduce time-to-market, frequent requirements changes during the project life-cycle, increase the failure chance of software projects when we analyze the time indicator in the software development process. The dissertation goal is to meet and to organize of software engineering practices and techniques in an organized roadmap aiming cycle time reduction in software development. In this roadmap, the practices are organized to help software planning, solution architecture, component based development definition, to promote reuse and concurrent engineering with purpose to reduce cycle time software development and improve productivity.

A realização de projetos dentro do prazo estabelecido é um fator comum em diversas áreas de produção como a engenharia civil, de aviação, química, transportes, indústria em geral, entre outras. No entanto, na engenharia de software, a questão do tempo na construção de um produto é um desafio de processo a ser superado em cada novo projeto. O cumprimento de prazos no desenvolvimento de software é tão crítico que o próprio controle de atrasos no ciclo de produção é um fator a ser considerado na análise de redução do tempo de desenvolvimento. A complexidade do ambiente de software, a competitividade de mercado, as mudanças de requisitos constantes durante o projeto e o tempo disponível cada vez mais restrito, aumentam as chances de insucesso quando analisado o indicador de tempo na produção de software. O objetivo deste trabalho é reunir e organizar as práticas e técnicas de engenharia de software em um roteiro que permita a redução do tempo no desenvolvimento do software. Neste roteiro, é descrita a utilização organizada e planejada das práticas de engenharia de software que auxiliam no planejamento, na criação da arquitetura de solução, na definição da infra-estrutura técnica para reutilização e a utilização da engenharia simultânea, visando proporcionar ganhos reais no tempo de produção do software e no aumento da produtividade. / The completion of software project within schedule is a common goal in several industries like building engineering, aviation, chemical, transport, wares and so on. However, in software engineering, the schedule is a process challenge from the beginning of each new project. The time is so critical that the delay control is an analysis point for cycle time reduction in software development. The complex environment, the pressure to reduce time-to-market, frequent requirements changes during the project life-cycle, increase the failure chance of software projects when we analyze the time indicator in the software development process. The dissertation goal is to meet and to organize of software engineering practices and techniques in an organized roadmap aiming cycle time reduction in software development. In this roadmap, the practices are organized to help software planning, solution architecture, component based development definition, to promote reuse and concurrent engineering with purpose to reduce cycle time software development and improve productivity.

Purpose - The purpose of the thesis is to record the content of the information shared by buyer to supplier in independent dyadic business relationships in the clothes manufacturing industry of Imbaba and Warrak, Great Cairo, Egypt. The objective is as well to describe how this sharing is managed in terms of communication frequency, order cycle time and information technology used. Methodology – A case study was performed on four companies in the clothes manufacturing industry of Imbaba and Warrak, Egypt. The empirical data was collected through six semi-structured interviews. The results were thereafter analyzed through a summarized framework. Findings - The content of shared information is mainly of traditional character, nevertheless do 50 % of the relationships as well include elements of additional soft information. When the information sharing is performed through regular communication do the frequency vary with an average of 0.43, once every 2.3 days. The order cycle times vary from delivery the same day as order placement to three days after order placement, with an average of 0.5 days. The information is shared through two different information technologies: face-to-face and telephone. Research implications – Imbaba and Warrak are considered one of the poorest districts in the Great Cairo region. The region has although seen great development the last 12-15 years and is today a main district for the industry of clothes manufacturing in Cairo. The role of information sharing yet appears to be poorly examined. Originality/value - Making the situation evident to the case companies will impact on their possibilities to make further improvements within the area of information sharing. Key words Information sharing, dependence, independence, dyad, content, frequency, order cycle time, information technologies. Paper type Bachelor Thesis

Aim of diploma thesis “Lean production of electronics” is to apply lean production on workplaces in concrete company. Object of thesis is to orientate in lean production and apply its individual methods on workplace. First part of thesis is dealing with theoretical preparation, understanding lean production and methods of lean production. Second part is dealing with analyzing production processes, application of methods of lean production and designing workplaces.

[pt] Os modelos e estudos de roteirização presentes na literatura focam, em geral, nos processos ocorridos desde que os veículos saem do centro de distribuição (CD) até ao seu retorno. Esta visão de roteirização da porta para fora do CD acaba por negligenciar uma etapa importante correspondente às operações de movimentação interna do CD, a qual tem influência direta na jornada de trabalho das equipes de entrega e consequentemente na produtividade de cada veículo. A importância da etapa das operações de pátio é bem visível quando analisado o fluxo de valor da cadeia de distribuição. A procura de uma melhor gestão do tempo das operações de pátio abre, assim, uma oportunidade de melhoria da eficiência das operações de distribuição. Esta dissertação foca na inclusão do gerenciamento das operações de pátio junto com a roteirização como forma de aumentar a produtividade da empresa e maximizar a utilização de recursos humanos e materiais. O modelo de gerenciamento desenvolvido utiliza simultaneamente técnicas de otimização e de simulação capazes de planejar e acompanhar as operações de distribuição de uma empresa, respeitando as normas trabalhistas e indicadores de qualidade pré-estabelecidos. O modelo busca melhorar o aproveitamento da jornada de trabalho das equipes de entrega embarcadas em cada veículo, através da minimização dos tempos não produtivos de pátio (recebimento, acerto de contas, conferência de carga, check list de veículo, etc.). A minimização do tempo das operações de pátio aumenta a disponibilidade de tempo de jornada de trabalho da equipe de entrega em rota, possibilitando o aumento do número de pedidos atendidos por cada veículo, sem impactar nas janelas de entrega impostas pelos clientes, estouro na jornada de trabalho e indicadores de qualidade. Para elaboração e aplicação deste trabalho, foram utilizados 3 softwares, um de simulação, outro de roteirização e outro de captação de dados em tempo real. A integração dos três permite captar informações da operação, tratar e simular os modelos e realizar roteirização de veículos, incluindo o tempo de pátio na fórmula de Tempo de ciclo do veículo. O modelo de operação desenvolvido foi aplicado na empresa BETA do segmento varejista de bebidas localizada no Centro-Oeste do Brasil. Os resultados obtidos, quando comparados com a atual operação da empresa, representam uma redução de custo no total de 685.234,00 Reais com a operação de distribuição. Especificamente, a racionalização do tempo de pátio permitiu uma melhoria de 2:15:15 em redução de filas no fluxo do pátio ao analisar o fluxo de saída e retorno. Teve ainda como consequência a melhoria da produtividade dos veículos passando de uma média de entrega de 25 para 31 entregas por dia. / [en] The models and studies of routing in the literature focus, in general, on the processes that have occurred since the vehicles leave the distribution center (CD) until their return. This vision of routing the door to the outside of the CD ends up neglecting an important step corresponding to the operations of internal movement of the CD, which has a direct influence on the workday of the delivery teams and consequently on the delivery productivity of each vehicle. The importance of the stage of yard operations is well visible when analyzing the value chain flow of the distribution chain. The search for better time management of yard operations thus opens up an opportunity to improve the efficiency of distribution operations. This dissertation focuses on the inclusion of yard operations management along with routing as a way to increase company productivity and maximize the use of human and material resources. The management model developed simultaneously uses optimization and simulation techniques capable of planning and monitoring the distribution operations of a company, respecting the labor standards and pre-established quality indicators. The model seeks to improve the utilization of the workday of the delivery teams embarked in each vehicle, by minimizing non-productive yard times (reception, accounting, cargo check, vehicle check list, etc.). By minimizing patio operations time we increase the time available for the delivery team to operate, and consequently increase the number of requests served by each vehicle, without impacting on the delivery windows imposed by the customers, work and quality indicators. During the elaboration of this work 3 softwares were used, one of simulation, another of routing and one of data acquisition in real time. The integration of the three allows you to capture information from the operation, treat and simulate the models and perform vehicle routing, including yard time in the Vehicle Cycle Time formula. The operating model developed was applied in the BETA company of the beverage retail segment located in the Center-West of Brazil. The results obtained, when compared to the current operation of the company, represent a reduction of cost in the total o BRL 685,234.00 with the distribution operation. Specifically, the optimization of patio time allowed for a 2:15:15 improvement in queue reduction in the patio flow when analyzing the outflow and return flow. In addition, the productivity of vehicles increased from an average delivery of 25 to 31 deliveries per day.