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Scheduling for accurate estimation of construction duration is significant to prevent construction delays and successfully complete projects on time. Although the main reasons for construction delays differ among developing countries, several factors related to project characteristics and clients contribute. In this study, interviews and observations were conducted with TOKI (Housing Development Administration of the Republic of Turkey), to explore construction delays. It was revealed that TOKI uses three factors such as “the number of flats”, “type of drawings utilized during the tender stage”, and “non-working days” to estimate total construction duration. Data analysis of the TOKI Projects Status Table, which lists detailed project information for 2800 completed TOKI projects, showed that most delays occurred in housing projects. Therefore, the construction delays for TOKI housing projects were investigated in this case study. The findings revealed that there is a wide construction duration gap between calculated construction durations using TOKI’s calculation method and durations indicated in official construction contracts between TOKI as a client and the awarded contractors. It was concluded that the comparison between durations with construction documents and schematic design and construction delays are generally positive and high. Therefore, it was found that TOKI significantly shortened the construction duration and the factors used by TOKI for calculation of the construction duration are insufficient, which ultimately resulted in delays for a considerable number of housing projects. These findings can be helpful for clients and project managers to mitigate construction delays. To effectively overcome construction delays in developing countries, suggestions are made to develop accurate construction duration estimation models. [ABSTRACT FROM AUTHOR]

An integrated problem for unrelated parallel machine scheduling with additional resources is considered in this study. In addition to resources such as machines or workbenches used in the production environment, there is also the use of additional resources. Additional resources can be used both in the setup and process stage. With the use of a common server as an additional resource in the setup stage, machine scheduling problem with common server arises. With the use of additional resources in the process phase, resourceconstrained machine scheduling problem occurs. By integrating these two separate problems, a single problem is defined, and a mathematical model is developed. Due to the complexity of the problem, metaheuristic methods are proposed for solving large-scale problems. The proposed methods are tested in randomly derived problems. The computation results show that the mathematical model for small-sized problems and simulation annealing algorithm for medium and large-sized problems achieved better results. [ABSTRACT FROM AUTHOR]

In this study, an optimization model has been developed to plan the restoration works envisaged to be done in historical buildings. There are very few studies in the literature on modeling the restoration works of historical monuments and cultural heritages, and most of these studies are based on multi-criteria decision-making models that aim to prioritize the works to be done. Restoration of historical monuments is an expensive and long process. Considering the cultural, social and economic importance of the buildings under the assumption that the works under restoration will be closed to visitors, the importance of optimizing the restoration works is understood. However, no study has been found in the operations research literature that deals with this problem in the scope mentioned. Where the minimum set of actions required to correct defects in a building is termed a 'work', it can be assumed that there may be more than one 'work' due to different defects in a building. Restoration works need to be assigned to work packages and scheduled according to the limited budget allocated for the restoration of the works. Since the budget is limited, the entire budget allocated for a certain period is reserved for only one work package. That is, work packages cannot be executed in parallel, a new work package cannot be started before a work package is completed. It is conceivable that similar types of work could be done by the same teams. There are economic advantages for similar works to be done by the same teams for different historical buildings located at close distances to each other. Under the assumption that the building will remain closed to use/visit before all the restoration works on a work are completed, it can be aimed to complete the restoration works of the buildings as early as possible. In this context, with the developed mathematical model, it is aimed to assign the works to the work packages by taking into account their similarity and geographical proximity, thus making optimal assignment and scheduling under limited budget conditions. [ABSTRACT FROM AUTHOR]

The causes and consequences of violence against healthcare workers need to be evaluated from different perspectives. Studies show that there is a communication problem, but this problem is not only between healthcare workers and patients. Especially the discourse used by external factors and the influence of the media are important in the occurrence of violence. From this point of view, improving the communication training given to healthcare professionals, regulating the discourse through the media and planning awareness activities are important factors for the solution of the problem. There is a clear relationship between individual physical violence and social discursive violence. The discourses of people who are followed or supported by many segments of the society can be applied more sharply by the followers in the lower segments. This situation occurs between three factors: The perpetrator of violence, The subject of violence, The cause of violence. What is reflected in the media and the law has always been the "perpetrator of violence" and the "victim of violence". The hidden subject is the one who causes the violence. This study is a retrospective study conducted by examining the discourses used by whom and for what purpose, examining the statements reflected in the media and reviewing the literature. Especially when the discourses of politicians, who are followed through the media, are evaluated in the case of health workers, the transformation of the action into violence increases significantly according to the negativity of the discourse. As a result of the evaluation of political messages in the past-present axis and their application in the context of the rights obtained, it makes it inevitable that violence will occur as a result of discourses and expressions that legitimize violence, even if they do not directly involve violence. Violence goes beyond the perpetrator and victim, as it leads to a mental coding of discourse and action. Exposure to violent expressions in the media can have a negative impact on society, and the use of non-marginalizing language is key to preventing the legitimization of violence. Healthcare workers may quit or leave the country due to feeling undervalued, and violent discourses can become physical over time. [ABSTRACT FROM AUTHOR]

Today, municipalities are key institutions about ensuring local development. In addition, municipalities play a leading role in the institutionalization of democracy, closest to the public, where the central government can share its power and authority. The strategic plans of the municipalities are the documents that explain their current institutional status and contain the policies, goals and objectives for the coming years. In this study, the issue of women has been sought in the strategic plans of the municipalities. In this respect, Istanbul Ankara and Izmir Metropolitan Municipalities, which have the most populous population in Turkey, are included in the scope of the study. Within the scope of the study, the latest 2020-2024 strategic plans and 2021 activity reports prepared by the relevant municipalities will be examined by focusing on the issue of women. In the study, document analysis technique, one of the qualitative analysis techniques has been used. [ABSTRACT FROM AUTHOR]

With the continuous increase in the population in our country and in the world, planning of public transportation and transportation systems and solving the problems experienced in this process is of great importance in order to provide environmental awareness, economic and social benefit. The issue of determining the optimum level of trip frequencies and number of trips in urban public transport systems is one of the most important problems and is a critical issue for all individuals living in the city. In this study; in order to plan urban public transport (bus) systems efficiently and sustainably; by examining the current situation number of daily trips, trip frequencies and passenger transport capacities of Tekirdağ / Çorlu Municipality public transportation systems, the number of trips has been optimized. For this purpose, a linear goal programming model was developed for the optimization of the number of daily trips. The model was solved with the help of the LINGO package program and the optimum number of trips per day was determined. In the study; detailed analyzes were carried out for the selected pilot bus line. The current state system design and optimum system design results were evaluated comparatively, and cost-benefit analysis was performed. [ABSTRACT FROM AUTHOR]

In today's competitive environment, businesses need to respond quickly and with high efficiency to the diverse and personal demands of customers in order to increase their competitiveness. In order to increase efficiency and flexibility in production systems, different production systems such as mass production (assembly line) produced by the American Ford company, Toyota Production System (TPS) developed by Toyota in Japan and cellular production system (CM) based on group technology (GT) have been developed. However, productivity is dropped in the assembly line and Toyota production system due to dynamic demands, short life cycle of products and high diversity. Japanese companies such as Sony and Canon have developed a Japanese cellular manufacturing system to meet market demands and to distinguish it from the traditional CM, they have called this production system a seru production system. There have been few studies in the literature on the seru production system. Especially in the Turkish literature, there are only two studies that considered seru production systems. With this aspect, this study is aimed to fill this gap in the literature. In this study, a comprehensive literature review has been conducted. In addition, a mathematical model is proposed for the conversion of the assembly line to the seru production system (line-seru conversion) and scheduling problems that minimize total tardiness. The GAMS package program is used to solve the model and the results are analyzed. [ABSTRACT FROM AUTHOR]

Projects are set of processes which aim to serve a unique product or a service in a time-bounded period. Pressure in terms of accelerating the time to market of the unique product or service has become the reality in every organization. Thus, companies need to search for new methodologies to schedule projects effectively. This paper presents a new mathematical model to schedule resource constrained projects in accordance with their logical relationships. Optimal solution of this complex model cannot be found in case of a high number of activities. Therefore, a new hybrid metaheuristic is proposed to find efficient solutions. Moreover, the proposed methodology is applied to schedule projects in a Turkish technology company. For 154 projects completed between 2018 and 2020, proposed methods finds on the average 3.91% better solution in 178 seconds compared to solutions obtained by CPLEX in 34,883 seconds. Proposed methods are also applied for 64 projects planned in 2021 and finds on the average 5% better results in 130 seconds compared to solutions found by CPLEX in 35,438 seconds. In brief, the proposed methodology provides efficient solutions with a very small number of delayed projects, reliable plans, better solution time and objective function value. [ABSTRACT FROM AUTHOR]

Course timetabling problem is one of the most common time scheduling problems that frequently encountered in universities and whole education institutions. To eliminate this problem requires notable amount of labour and supply and in several education institutions, this scheduling is done manually but it doesn't occur as desired and causes to loss of time. Course timetabling problem is the assignment of courses to appropriate time periods, considering the constraint structures specific to the educational institutions. Constraints may depend on different factors such as the specific rules of the educational institution, capacity constraints, legal regulations, faculty and students' preferences. In this study, two new 0-1 integer programming models were proposed by considering preferences of the faculty members, and the models were tested with the application in a state university. In first proposed model, while the total gladness value is desired to be maximized by considering the time-slot preferences of lecturers, the conflict of courses is tried to be minimized. In the second proposed model, the differences in gladness value between lecturers are aimed to be minimized in addition to first model objectives. The proposed models were solved with GAMS 23.8.2 software, and alternatives that could be suitable for decision makers were presented. [ABSTRACT FROM AUTHOR]

Purpose: The study reveals the effects of group-based reading activities planned by the researchers on the process of acquiring reading culture and developing reading skills and habits of high school students. Method: The study is action research. The data were obtained from nine 11th grade students selected by purposive sampling technique, studying in Danışment Gazi Anatolian High School affiliated to Niksar District Directorate of National Education. The data were collected via interview and observation forms developed by the researchers. The descriptive analysis technique was used to analyze the data collected via interview forms. Observational data were analyzed with the t-test. Findings: The findings show that there is a significant difference in the students' reading performance in favor of their final week scores. The activities contribute to student development, help them develop a reading habit and read more effectively, and positively affect their perception of the book. Implications: According to the results, the students' reading skills and habits improved significantly. In addition, they think that the reading activities contribute to their reading skills and that the practice can be carried out in all schools. Originality: The study is original as it provides a design for the process of acquiring reading culture and reveals empirical data, practitioner observations, and student views on the effects of this process. [ABSTRACT FROM AUTHOR]

Design and planning areas seek solutions to the technical, aesthetic and functional requirements of the spaces for social and economic needs. These solutions focus on the mutual benefits of spaces and their users. While every space exists for a user, the expectations of the user from the place manage this existence process. From the smallest scale to the largest scale, the design process is a collocation where the designer evaluates the function of the space and the expectations of the space users together. This collocation action also includes the organization created by a process. For this reason, it is important to investigate the design requirements that have existed from the beginning or emerged over time in the design and planning process of architectural structures. This study aims to determine the process starting from the perception of space and the necessity of the spatial arrangement method in order to prepare a design guide for environmental character and experiential evaluations as a requirement of the spatial organization. [ABSTRACT FROM AUTHOR]

Parallel machine scheduling problems have many practical and industrial applications and have recently been the subject of research by many researchers. However, sometimes machines can be unavailable for a period of time for reasons such as machine failure and maintenance operations. The lack of studies in the literature considering such restrictions has been the motivation for this study. In this study, the unrelated parallel machine scheduling problem is discussed with the assumption that the machines will not always be available and they will not be able to perform some tasks. In addition, sequence-dependent setup times between tasks were also taken into account. The objective function is to minimize total tardiness and earliness. A mixed integer mathematical model is presented for the problem and solved with the GUROBI 9.0 solver. Due to the NP-hard nature of the addressed problem, a tabu search (TS) algorithm is proposed. Experimental results show that the proposed TS algorithm has a good performance. [ABSTRACT FROM AUTHOR]

This paper shares the program and content of the 49th IASL 2021 Annual Conference that organized in the field of school librarianship. This report summarizes some of the presentations that I attended and watched within my scope of interest, because of intensive program content. Due to pandemic, conference broadcasted virtually from Denton, Texas. So the original conference program time schedule is different from Turkey regional time. [ABSTRACT FROM AUTHOR]

In this study, language and education discussions in Rojî Kurd and Hetawî Kurd periodicals were examined. These two periodicals were official publication organs of the Kurdish-Student Hevi Association, the first legal Kurdish student association active in two periods between 1912-1914 and 1918-1920 in the last years of the Ottoman Empire. These discussions were evaluated in the light of language planning categories in order to determine the limits of the language planning for Kurdish at that time. For this purpose, content analysis of Rojî Kurd and Hetawî Kurd periodicals was carried out. Then, the language and educational articles and their discussions in these publications were examined and the ideas, suggestions and practices in these discussions were interpreted in accordance with the categories of language planning. [ABSTRACT FROM AUTHOR]

Due to rapid urbanization and population growth, the use of the rail transportation system is gradually increasing. However, the widespread use of rail transportation systems in urban transport causes large-scale and difficult-to-solve problems. In particular, many problems arise, such as imbalances in the planning of train trips, inability to adjust shift scheduling and working-rest periods of the machinists. For this reason, it has become obligatory to generate fast and appropriate solutions to the problems in order to plan, operate and maintain these systems. In this study, it is aimed to create a fair task schedule by equalizing the total working time and the number of shifts of all the machinists of a company serving in the light rail transportation system. In the current situation, it is very timeconsuming to manually perform the task schedule of the machinist. In addition, the lack of equal work distribution in the schedule created leads to employee dissatisfaction. Therefore, in this study, the goal programming model for the machinist scheduling problem has been developed and solved by using GAMS/CPLEX program. With the proposed mathematical model, fair task assignment has been achieved and it is expected that the quality of service will increase with the increased motivation and satisfaction of the employees. [ABSTRACT FROM AUTHOR]

With the use of computers in every field, the usage intensity of processors is increasing day by day. In order to cope with this intensity, processors need to be constantly updated and improved. Various scheduling algorithms are being developed every day in order to continuously improve and accelerate the processors and to cope with the processing intensity. The main purpose of the scheduling algorithms is to increase the efficiency of the processor. For this, the processor needs to make a planning between the pending processes. Planning can be done by giving different priorities or using different methods. In order to increase the efficiency of the processor, in this paper, existing algorithms were examined. Round Robin Algorithm was improved using Genetic Algorithm. It is aimed to find the optimum values by selecting the quantum value according to the pending processes and their parameters. When the developed new method compared with the existing standard algorithms, it is observed that the waiting time and the turnaround time were shorter than the other algorithms. [ABSTRACT FROM AUTHOR]

The logistics industry has to deal with the difficulties arising from the intensity of the pandemic recently, as well as the problems such as reducing the increasing costs and planning transportation activities. Firms also have responsibilities in the reverse logistics activities. In the context of environmental responsibility, it is extremely important to determine collection points so that recyclable products can be collected in specific centers to be included in the reverse logistics process. In this study, it was aimed to determine the collection points of recyclable products for 19 cities in the Black Sea region. Due to the geographical conditions of the Black Sea region, the analysis was carried out by considering 3 regions, namely the eastern, central and western Black Sea. To determine recycling collection points, simulated annealing method, one of the heuristic technique developed for continuous optimization problems were used and 3 reverse logistics recycling collection points were proposed for the Black Sea region. [ABSTRACT FROM AUTHOR]

In this study, we develop an algorithm for a bi-criteria scheduling problem that minimizes the maximum weighted tardiness and total weighted flow time. While the algorithm is capable of generating all nondominated points, the algorithm is designed to generate a subset of the nondominated points that guarentee to represent the whole nondominated set based on a prespecified quality measure. We apply the algorithm on a wide variety of problems with different properties. The results of the experiments show that the algorithm works well not only in terms of the solution time but also the number of schedules presented to the decision maker. [ABSTRACT FROM AUTHOR]

Project planning has a significant role in project management to progress regularly and complete the project on time. The studies for Resource Constrained Project Scheduling problem, where the available resource is limited, indicate that since there is no priority for finding the optimum solution for all problems, the choice of priority rule affects the success of planning. In this study, priority rules used for the solution of Resource Constrained Project Scheduling problem, where the duration of the work packages and the requested resources are determined, are examined. When the shortest schedule generation numbers are compared, it was seen that Maximum Area rule, which prioritizes the work package with the highest value obtained by multiplying the duration and amount of resource usage of the package, and Longest Processing Time rule, which prioritizes the work package with the highest process time, were successful. According to the average deviations, Highest Resource Usage rule, which prioritizes the most resource-consuming work package yielded successful results. Hence, two different approaches, "Area and Processing Time" and "Area and Resource Usage", have been proposed. The success of the proposed approach was measured by using PSPLib j30, j60, and j120 datasets. The results indicate that hybrid "Area and Resource Usage" rule produces good results for both in the number of shortest schedule generation and average deviations. [ABSTRACT FROM AUTHOR]

Readings on the city and architecture are mostly based on certain breaking points. 1950, the year when the Democrat Party came into power, is an important breaking point in this regard. The single-party period began to be debated during World War II and Turkey entered a multi-party system in 1945, holding its first multi-party elections in 1946. The single-party period ended with the 1950 elections, heralding a new political era. This new era saw the end of statism and the birth of a new economic approach driven by the private sector. Socially, life in this period was built on what can be expressed as a rapprochement with America. Another breaking point in this context is 1960, the year the Democrat Party rule ended. The new era corresponds to a time period in which the principles of the social state as well as planned economic policies were implemented, while youth organizations and anti-American movements gained weight. As in other fields, the Democrat Party, which was in power between 1950-1960, caused important changes in the field of architecture, and has become the subject of many studies on the search for new architectures, emerging building types, and planning activities in the cities. Ulus İşhanı and Emek İşhanı are two buildings that exemplify the new building types of this period. This article makes an urban and architectural assessment of these two buildings, which made headlines in recent years, to carry out a periodic reading. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the relationship between time management skills and academic success. 562 students studying at the Nursing department of a university who agreed to participate in the study were included in the sample of this descriptive study. The students were found to have moderate level time management skills. While no significant difference could be found between the academic success grade averages of the students and the mean time planning and time consumers sub dimension scores of the Time Management Inventory; the time management applications of the students with an academic success grade average higher were found to be better, and these students were found to manage their time better and plan for longer time ranges. In the regression analysis performed, the variables of time management general score and time attitudes sub dimension score were found to be significant predictors of academic success. The time management skills of nursing students were found to be on a moderate level with time management affecting academic success on an important level. [ABSTRACT FROM AUTHOR]

This study aims to determine the impact of ERP implementation. To achieve this purpose, a survey was conducted on the companies that have been successful in ERP implementation by sending out a questionnaire. Then, the company characteristics, their ERP program features, and factors that are effected by ERP implementation were analyzed. The results of the survey have shown that after ERP implementation, some of the factors have improved. These factors are integration of departments, incorporation of technologies in the organization and achievement of standardization, regular documentation and reporting, work dispatch and usability of data in decisionmaking, costs, lead time of raw material, ratio of customer satisfaction, delay time of production, on time for orders' delivery, planning time and decision-making time, production / service productivity. [ABSTRACT FROM AUTHOR]

This study deals with a job allocation and scheduling problem of batch processing ovens belonging to a factory that manufactures welding electrodes. Each electrode type may not be heated on all of the ovens. Besides, there exists a priority order of ovens for each electrode type. The other inputs are; work order amounts of electrodes, the ready times, heating times, cooling down times, and the capacity of each oven with respect to the electrode types. The work orders with the same heating time may be heated simultaneously without exceeding the oven capacity. For the defined problem, an integer programming model is developed. The objective function is to assign the work orders to the preferred ovens as possible and to maximize the utilization rates of ovens. The model determines which work order will be heated on which machine and in which time interval. The model results are launched for two different work order sets. Finally, by discussing the results, the applicability of the model is demonstrated. [ABSTRACT FROM AUTHOR]

The timetabling of courses and examinations is a challenging and time consuming activity for all educational institutions, especially universities. The course scheduling problem is a type of timetabling problem that is concerned with assigning a number of courses and instructors to the most suitable classrooms and time-slots, subject to some constraint structures on characteristics of the problem and institutions. In this paper, we analyze the main points of the outstanding studies that have conducted on the problem since 1960. In addition, solution approaches that have been applied by researchers to solve the problem, including operations research based methods, metaheuristicbased methods and some novel methods are analyzed. [ABSTRACT FROM AUTHOR]

Increasing population forces us to find the best ways of using the existing energy resources. In search of the best ways there is a higher need for optimisation applications. It is observed that applications in the energy fields are mainly focused on minimizing the investments, maximizing the efficiency of technological designs, and minimizing the operational costs. Operations scheduling or load planning as named in the energy field, is important in minimizing the operational costs. Besides, scheduling is one of the basic fields of operations research that is why it is a field of continuous improvement in line with the changes in the energy field. This research aims to analyse the scheduling literature to depict the subjects least studied. Our article handles the publications of research on scheduling with the objectives, decision variables, constraints, methods and the achievements. Furthermore, the uncertainties handles in primal energy or renewable energy utilization are covered by the analysis performed. The scheduling optimization studies found in literature is clustered using self-organizing maps (SOM) in order to observe the frequency of subjects analysed. This study confirming the literature survey and clustering of existing studies will lead the researchers working on energy systems scheduling. [ABSTRACT FROM AUTHOR]

Mixed model assembly line can adapt to the varied small size batch production, by keeping of minimum inventory despite of product diversity and ability of quick response to the abrupt change of demand. Due to the mentioned attributes of mixed model assembly line, waiting/ accumulations are in question. In this study, the production smoothing model is presented for solving this problem. The smoothing production aims to reduce the size of batches and streamline the flow of products/ parts/ raw materials throughout the whole system. In this study, the solution of models that response to demand for certain time at "just in time" according to the JIT approach and "no stock" according to the Lean philosophy in mixed model assemble line in automotive firm. The problem is handled for 50 products with two approaches as scheduling and sequencing. In scheduling stage, three solving methods are presented and alternative solutions are obtained for balanced production desired by the firm and considering constraints. These solutions are compared with several criteria. In sequencing stage, the work sequence of automobile models in assemble line is determined with modified Goal Chasing method. [ABSTRACT FROM AUTHOR]

In the service industry, customer satisfaction becomes more difficult with each passing day, employers have looked for new paradigms and ways to make service quality better and to keep service facilities reliable. Therefore, with the purpose of increasing their competitive power, employers give more importance to their employees who have direct relation with customers than they do to their customer. One of the new paradigms is make working hours flexible. In this study, an integer programming model is proposed for the nurse scheduling problem in the hospitals which are one of the most important service industries. On the contrary of classical nurse scheduling model, developed model has made flexible to starting time. The main aim of the model is make a schedule for nurses according to their preferences. The developed model is applied on a surgery department of one university hospital with real data. According to results, model can satisfy 99,6% of the nurses with their schedule based on their preferences. [ABSTRACT FROM AUTHOR]

In mass customization using resources efficiently with changing customer demands and manufacturing conditions is vital, since in today's competitive market conditions, this efficiency provides cost, time and labor savings to companies. In production environment, Process Planning (PP) and Scheduling are two functions that provide efficient usage of resources. Isolation and long time gap between these functions are main problems affecting the effiency of production. In this study, to solve the problems of productivity, it is aimed to build an integrated system which is able do PP and Scheduling in parallel and respond quickly to fluctuations in job floor. In existing integration models aiming to eliminate this isolation and time gap, it has been observed that if the search and solution space expands, the computational time increases rapidly. Therefore, in this research, a hybrid optimization approach, which can find the optimal solution rapidly is considered and a hybrid model combining both Genetic Algorithm (GA) and Artificial Neural Network (ANN) is proposed. To improve GA performance and increase the effiency of searching, clustering activities are carried out for building new cromosome structures. To increase population diversity, effective genetic operator schemes and efficient genetic represantations are used. In the integration module, 3 different GA structures created within the scope of our research are compared and the algorithm formed by clustering method shows better performance than the others. In this paper by using ANN method, a new system trained by data obtained from Scheduling is generated and this system is able to quickly respond the changes in shop floor and provide new schedules instantly. In rescheduling module, ANN's performance measures provide evidence to accuracy of Heuristic solution generated by Integration module. [ABSTRACT FROM AUTHOR]

In this study, a special type of identical parallel machine scheduling problem with n products and m identical machines is considered to determine that the products should be produced in which machine and order at the plant of Eti Companies Group. The multi-objective goal programming model with special process constraints is proposed for this problem. Since size of this kind of problems is usually large in real life, they cannot be solved with exact solution methods. Therefore, a genetic algorithm with an original crossover operator is developed for solving this problem. The effectiveness of the developed solution approach is tested on small, medium and large size randomly generated test instances. Finally, the results obtained for the real-life problem are discussed. [ABSTRACT FROM AUTHOR]

In this paper, the vehicle routing problem with time windows and multiple use of vehicles (VRP_TW_MUV) which is the generalized version of the classic vehicle routing problem, is considered. Unlike the classic Vehicle Routing Problem, vehicles are allowed to use more than one route in the VRP_TW_MUV. The VRP_TW_MUV is encountered usually in the distribution systems in which the product's shelf-life is short or duration of the distribution is short. Although, the VRP_TW_MUV is often encountered in practice, there are very few studies in literature. In this study, a mathematical model proposed for the VRP_TW_MUV. The proposed mathematical model is compared in terms of time to reach the best solution on the test problems of various sizes derived from the literature. [ABSTRACT FROM AUTHOR]

Setup times have an important effect on providing quick response to the internal as well as external customers. In addition to eliminating setup activities, jobs with sequence dependent setup times should be scheduled efficiently so as to reduce setup times. In this paper, a scheduling systematic which considers product design characteristics is considered. With respect to the roadmap of the systematic, a product design characteristics oriented sequencing algorithm with the aim of decreasing the total of sequence dependent setup times is proposed and sequencing algorithms are reviewed. When evaluating the performance of sequencing methods, the cable cutting-stripping-crimping process of a real wiring harness production system is focused. Performance comparison of the sequencing algorithms are based on deviation from lower bounds for total setup time and applied job sequences. [ABSTRACT FROM AUTHOR]

Scheduling is an assignment making process normatively in specific time intervals by regarding resource constraints. Preparation process of syllabus is one of the scheduling types for educational institutions. The purpose is placement of term courses to the timeline in the framework of determined constraints. In educational institutions, syllabus is usually prepared manually by administrators. In this study, a programme that does not require manual preparation and prepares a syllabus automatically has been developed. In the programme, term courses of Süleyman Demirel University Gelendost Vocational School and course assignments have been used. By examining the previous studies and regarding the needs of Gelendost Vocational School, constraints of problem have been determined. To solve the problem, in C# programming language, using artificial bee colony algorithm, a programme with an interactive user interface has been developed. As a result of studies, a suitable course schedule has been formed with used algorithm and taken reports of these schedules. [ABSTRACT FROM AUTHOR]

To gain the ability of designing, scheduling, and manufacturing the products, which customers exactly demand, in time provides competitive advantage to companies. The above mentioned ability is provided by implementing pull system between the costumer and supplier as well as manufacturing processes instead of push system. Such an approach is the reflection of being costumer oriented in production. In addition, setup time constitutes an important part of production lead time. Pull systems lead to significant achievement in terms of lead time when applied in the environment of short setup times which allows production in small batches. Scheduling problems are related to manufacturing resource planning (MRP) in the industrial context. Production managers must select an appropriate scheduling approach that will provide cost-efficient running of the production system. A scheduling approach that guarantees the cost efficient running of the factory is to minimize operational costs that include setup costs (times) which are very important in manufacturing industries. The setup time has often been considered to be negligible or as a part of the processing time. Other-wise, setup times are considered in two types, namely sequence independent and sequence dependent setup times. Sequence independent setup time depends only on the job to be processed while sequence dependent setup time depends on both the job to be processed and the immediately preceding job. Parallel machine problems, where each job can be processed on any of the machines but needs to be processed by only one machine, have a high level of importance in industrial scheduling because of the fact that many examples of the use of parallel machines can be found in the real world. The measurement of sequence dependent setup times becomes inefficient in terms of cost and time in production systems where increased product variey exists. Furthermore, in such systems, it is very difficult to update measured sequence dependent setup times. In this context, it is very efficient to utilize product design characteristics for the estimation of sequence dependent setup times. What is more, it is known in practice that controlling input rate has a great impact on the system performance. In manufacturing systems, this input regulation is performed by the Order Review/Release (ORR) function. Regarded as an effective capacity management tool, ORR manages the transition of production orders from the planning system to the shop floor. In ORR, production orders, that may be generated from a requirements planning system or directly originated from customer orders, are not immediately released to the shop floor without considering any information about the system or job characteristics. These jobs are often first collected in a preshop pool and then released to the system according to specific conditions. In this sense, ORR procedures can be considered as the link between production planning and production control as well as the link between manufacturing strategy and day by day management. The purpose of ORR is to improve system performance by controlling the flow of production orders to the system (i.e., the timing and conditions of order release decisions). These improvements can be achieved in terms of increased flexibility, decreased work in process (WIP), improved delivery performance, and decreased congestion and manufacturing lead times. When the relevant literature is reviewed, it is seen that there is not any scientific guiding work which not only considers product design in job scheduling, but also aims to prevent overproduction waste. In this thesis, an integrated methodology that uses product design specifications for job scheduling under the principle of Order Review/Release is developed. The proposed methodology is applied to a real wire harness industrial problem involving the cutting of cables with different colors, sizes and terminals on identical parallel machines with long sequence dependent setup times. The sequence dependent setup times are determined via a mathematical model without measurement. The scheduling objective is to minimize total sequence dependent setup time. [ABSTRACT FROM AUTHOR]

In this study, vehicle routing problems with hard time windows and simultaneous pick up and delivery are determined and mathematical model is developed. Generally the goal of vehicle routing problems is minimization of travelling distance or travelling cost. In the literature it is observed that vehicle routing problems with time windows have also the same goals with vehicle routing problems. However, waiting time resulted from time windows must be considered for vehicle routing problems with time windows. In this study, objective function of the mathematical model of the determined problem is chosen as waiting time minimization. Solomon Benchmark Problems are revised to adapt for the problem structure and results are obtained by using GAMS. [ABSTRACT FROM AUTHOR]

System information can be transferred into computer environment with more accuracy than ever before and simulation can be used efficiently with the development of object oriented programming. It is important integration of system data into the software by using work flow plan drawings with scheduling of simulation results on a Gantt diagram when searching alternative structure and flow organizations in simulation of production systems. In this study, a flexible work flow editor is developed to model system data and work processes and to draw real time Gantt diagrams as a part of the research project of "Development of Simulation Software for Facility Organizing, Production System Structuring, and Performance Measuring (Faborg-Sim)" which is supported by TUBITAK-MAG. [ABSTRACT FROM AUTHOR]

The absence of a decision support system for scheduling production of laundry powders causes Unilever Gebze Plant to incur opportunity costs due to increasing number of setups. It is intended with this project to design a fast and consistent scheduling system which minimizes the number of setups in a continuous manufacturing environment. The problem has been studied with a compact model, a decomposed model with and without valid inequalities and finally with a heuristic method. It is found out that the heuristic method generates consistent solutions very quickly. Heuristic method has been integrated into Unilever Gebze Plant's scheduling system with a graphical user interface. [ABSTRACT FROM AUTHOR]

In this study, a decision support system is designed to optimally determine the set of routes and shipment schedules to be used for collecting materials from domestic suppliers to be delivered to Arçelik Dishwasher Company. The system consists of three main components: A mathematical model, a simulation model, and an interface program. In case of minor changes in demands or in the current set of suppliers, the simulation model is used to evaluate solutions that are proposed in response to changes. For major changes, the mathematical model is solved relative to the new situation and a new optimum is obtained. The interface program allows to use both models with ease and without having to rely on technical knowledge. [ABSTRACT FROM AUTHOR]

When a task or work is done continuously, there will be an experience so following times needs of required resources (manpower, materials, etc.) will be reduced. This learning curve described first by Wright. Wright determined how workmanship costs decreased while proceed plain increasing. This investigations correctness found consistent by plain producers. Learning effect is an effect that, works can be done in shorter time in the rate of repeat of work with repeating same or similar works in production process. Nowadays classical production systems adapted more acceptable systems with new approaches. Just in time production system (JIT) philosophy is one of the most important production system philosophies. JIT which is known production without stock stands on using all product resources optimum. Minimization problem of Earliness/Tardiness finishing penalty, which we can describe Just in time scheduling, appeared by inspired from JIT philosophy. In this study, there is literature survey which directed to earliness/tardiness performance criteria and learning effect processing in scheduling and as a result of this it is obtained some establishing for literature. [ABSTRACT FROM AUTHOR]

The phenomenon of the learning effect has been extensively studied in many different areas of operational research. However, there have been a few studies in the general context of production scheduling; also there have been fewer studies in flow-shop. Until the beginning of 1990 Earliness/Tardiness (E/T) problem was known as weighted absolute deviation problem. Not only tardiness but also earliness is very important performance criteria for scheduling problem. While total tardiness criteria provides adaptation for due date (ignoring results of earliness done jobs), it deals with only cost of tardiness. However this phenomenon has been started to change with Just in Time (JIT) production concept. Earliness is as important as tardiness on JIT production. In this study, the integer programming was suggested to take in to consideration "weighted E/T performance criteria and learning effect process property at the two machine flow-shop scheduling" and solution results was evaluated with sample problems by us. [ABSTRACT FROM AUTHOR]

When a task or work is done continuously, there will be an experience so following times needs of required resources (manpower, materials, etc.) will be reduced. This learning curve described first by Wright. Wright determined how workmanship costs decreased while proceed plain increasing. This investigations correctness found consistent by plain producers. Learning effect is an effect that, works can be done in shorter time in the rate of repeat of work with repeating same or similar works in production process. Nowadays classical production systems adapted more acceptable systems with new approaches. Just in time production system (JIT) philosophy is one of the most important production system philosophies. JIT which is known production without stock stands on using all product resources optimum. Minimization problem of Earliness/Tardiness finishing penalty, which we can describe Just in time scheduling, appeared by inspired from JIT philosophy. In this study, there is literature survey which directed to earliness/tardiness performance criteria and learning effect processing in scheduling and as a result of this it is obtained some establishing for literature. [ABSTRACT FROM AUTHOR]

In traditional scheduling problems, most literature assumes that the processing time of a job is fixed. However, there are many situations where the processing time of a job depends on the starting time or the position of the job in a sequence. In such situations, the actual processing time of a job may be more or less than its normal processing time if it is scheduled later. This phenomenon is known as the "learning effect". In this study, we introduce a time-dependent learning effect into a single-machine scheduling problem. The objective function of the problem is minimization of the maximum lateness. This study shows that EDD rule, which guarantees the best solution in classical situation (without learning effect), can not guarantee the best results in the situation with learning effect. In addition, a non-linear programming model is proposed for this problem, and solutions are found for problems which have up to 14 jobs. [ABSTRACT FROM AUTHOR]

The majority of research on scheduling problems addresses only a single criterion while the majority prodution planning problems require the decision maker to consider more than a single criterion for making a decision. In this paper, a problem with uncertain time parameters such as processing times and due dates in the m-machine flow shop scheduling problem, which has a big importance in nowadays manufacturing systems, is considered. Further a multiobjective approach based on genetic algorithm, optimizing fuzzy makespan, fuzzy maximum tardiness and fuzzy total flow time objectives simultaneously, is developed. The algorithm is developed to obtain efficient solutions. In this algorithm the values of the multiobjective function are expressed by using membership functions. The effectiveness of the algorithm is illustrated by using small size problems. The best parameter sets of the genetic algorithm are determined by using factorial design of experiment. It is shown that the algorithm produces efficient solutions for medium and large size problems in a reasonable amount of time. [ABSTRACT FROM AUTHOR]

Scheduling aircraft landings is a major problem in air traffic control area of congested airports. It is a special type of machine scheduling problem; processing times are sequence dependent, and there are penalties for jobs that are not completed on target time. Each plane has an allowable predetermined time window for landing. The objective is to optimally land a set of planes on one or several runways in such a way that separation criteria between all pairs of planes are satisfied. If efficient algorithms can be developed to assist the controller who is in charge of making scheduling decisions, then more effective use of fixed runway capacity will result. We tried to solve the problem using Ant System metaheuristic, which is gained more popularity in recent years. Using Ant System metaheuristic, we present a generic decision making tool that can be used both for the single runway and the multiple runway landings and takeoffs. Computational results are presented for the standard test problems obtained from literature. Results are compared with the previous works and show that Ant System solutions can be effective in practice. [ABSTRACT FROM AUTHOR]