Showing papers on "Job shop published in 1992"
TL;DR: In this article, an approximation algorithm for the problem of finding the minimum makespan in a job shop is presented, which is based on simulated annealing, a generalization of the well known iterative improvement approach to combinatorial optimization problems.
Abstract: We describe an approximation algorithm for the problem of finding the minimum makespan in a job shop. The algorithm is based on simulated annealing, a generalization of the well known iterative improvement approach to combinatorial optimization problems. The generalization involves the acceptance of cost-increasing transitions with a nonzero probability to avoid getting stuck in local minima. We prove that our algorithm asymptotically converges in probability to a globally minimal solution, despite the fact that the Markov chains generated by the algorithm are generally not irreducible. Computational experiments show that our algorithm can find shorter makespans than two recent approximation approaches that are more tailored to the job shop scheduling problem. This is, however, at the cost of large running times.
1,107 citations
TL;DR: In this paper, search heuristics are developed for generic sequencing problems with emphasis on job shop scheduling, and two methods are proposed, both of which are based on novel definitions of solution spaces and of neighborhoods in these spaces.
Abstract: In this paper search heuristics are developed for generic sequencing problems with emphasis on job shop scheduling. The proposed methods integrate problem specific heuristics common to Operations Research and local search approaches from Artificial Intelligence in order to obtain desirable properties from both. The applicability of local search to a wide range of problems, and the incorporation of problem-specific information are both properties of the proposed algorithms. Two methods are proposed, both of which are based on novel definitions of solution spaces and of neighborhoods in these spaces. Applications of the proposed methodology are developed for job shop scheduling problems, and can be easily applied with any scheduling objective. To demonstrate effectiveness, the method is tested on the job shop scheduling problem with the minimum makespan objective. Encouraging results are obtained.
520 citations
Proceedings Article•
01 Jan 1992
287 citations
TL;DR: This work considers the scheduling problem in which jobs with release dates and delivery times are to be scheduled on one machine, and presents a 4/3-approximation algorithm for the problem with precedence constraints among the jobs, and two polynomial approximation schemes for the problems without precedence constraints.
Abstract: We consider the scheduling problem in which jobs with release dates and delivery times are to be scheduled on one machine. We present a 4/3-approximation algorithm for the problem with precedence constraints among the jobs, and two polynomial approximation schemes for the problem without precedence constraints. At the core of each of the algorithms presented is Jackson's Rule-a simple but seemingly robust heuristic for the problem.
159 citations
TL;DR: Three scheduling principles are proposed that can significantly improve the performance of a two-station job-shop; in particular, better due-date performance can be achieved by ignoring due-dates on the shop floor.
Abstract: We define a job-shop scheduling problem with three dynamic decisions: assigning due-dates to exogenously arriving jobs, releasing jobs from a backlog to the shop floor, and sequencing jobs at each of two workstations in the shop. The job-shop is modeled as a multiclass queueing network and the objective is to minimize both the work-in-process WIP inventory on the shop floor and the due-date lead time due-date minus arrival date of jobs, subject to an upper bound constraint on the proportion of tardy jobs. A general two-step approach to this problem is proposed: 1 release and sequence jobs in order to minimize the WIP inventory subject to completing jobs at a specified rate, and 2 given the policies in 1, set due-dates that will attempt to minimize the due-date lead time, subject to the job tardiness constraint. A simulation study shows that this approach easily outperforms other combinations of traditional due-date setting, job release, and priority sequencing policies for two cases moderately loaded and heavily loaded of a particular shop. As a result of the study, three scheduling principles are proposed that can significantly improve the performance of a two-station job-shop; in particular, better due-date performance can be achieved by ignoring due-dates on the shop floor. Although we have only considered a two-station shop, the approach and scheduling principles presented here might also be useful for larger shops.
141 citations
TL;DR: In this article, the problem of obtaining a cycle time that is smaller than a given value in a strongly connected event graph, while minimizing an invariant linear criterion, is addressed.
Abstract: The problem of obtaining a cycle time that is smaller than a given value in a strongly connected event graph, while minimizing an invariant linear criterion, is addressed. This linear criterion is based on a p-invariant of the strongly connected event graph under consideration. Some properties of the optimal solution are proved, and a heuristic algorithm and an exact algorithm which make it possible to reach a solution to the problem are given. Applications of the results to the evaluation of job shops and Kanban systems are proposed. >
111 citations
TL;DR: This paper investigates the effects of partitioning job shop work centers to implement cellular manufacturing and shows that partitioning leads to adverse effects on flow characteristics, and introduces new parameters relevant to this context, the breakeven setup reduction factor and flow ratio.
Abstract: This paper investigates the effects of partitioning job shop work centers to implement cellular manufacturing. Analytical models are utilized to show that partitioning leads to adverse effects on flow characteristics. The setup reduction introduced in partitioned systems has to overcome these adverse effects before leading to the benefits associated with cellular manufacturing. It is shown that partitioned systems with an insufficient degree of setup reduction are inferior to unpartitioned systems. Two new parameters relevant to this context, the breakeven setup reduction factor and flow ratio, are introduced for the design of viable cellular manufacturing systems. These insights are verified using a shop-level simulation experiment, assuming non-Markovian conditions. The experimental factors include lot size, setup reduction factor, cell size and allowance of inter-cell movements. It is shown that the results are consistent with analytical insights in indicating the range of parameters in which cellular manufacturing may compare favorably with the best of the functional-layout systems.
108 citations
TL;DR: It is shown how the structural properties that are recently derived for single and multiple stage queueing systems can be used effectively in the solution of certain design optimization problems.
Abstract: Design issues in various types of manufacturing systems such as flow lines, automatic transfer lines, job shops, flexible machining systems, flexible assembly systems and multiple cell systems are addressed in this paper. Approaches to resolving these design issues of these systems using queueing models are reviewed. In particular, we show how the structural properties that are recently derived for single and multiple stage queueing systems can be used effectively in the solution of certain design optimization problems.
107 citations
TL;DR: In this paper, an integrated job shop planning and scheduling model is considered, where a multi-pass decomposition approach is used to solve the problem of solving a planning problem with a fixed sequence of products on the machines, and a job shop scheduling problem for a fixed choice of the production plan.
Abstract: We consider an integrated job-shop planning and scheduling model. To solve the problem we use a multi-pass decomposition approach which alternates between solving a planning problem with a fixed sequence of products on the machines, and a job-shop scheduling problem for a fixed choice of the production plan. The generated production plans are feasible i.e., there exists at least one feasible schedule to realize that plan. Quality of the solution is investigated and numerical results are presented.
94 citations
TL;DR: In this paper, the authors investigate the performances of machine and AGV scheduling rules against the mean flow-time criterion in an FMS simulation model and test them under a variety of experimental conditions.
Abstract: Although a significant amount of research has been carried out in the scheduling of flexible manufacturing systems (FMSs), it has generally been focused on developing intelligent scheduling systems. Most of these systems use simple scheduling rules as a part of their decision process. While these scheduling rules have been investigated extensively for a job shop environment, there is little guidance in the literature as to their performance in an FMS environment. This paper attempts to investigate the performances of machine and AGV scheduling rules against the mean flow-time criterion. The scheduling rules are tested under a variety of experimental conditions by using an FMS simulation model.
80 citations
TL;DR: Key structural properties of cyclic schedules are studied and a search algorithm based on these properties is proposed, and preliminary computational tests of the algorithm are reported.
Abstract: We consider the problem of finding cyclic schedules for a job shop in which all jobs are identical. Specifically, we assume that a single product is produced on a finite number of machines. Each part is manufactured by performing a given set of operations in a pre-determined sequence. Each operation can be performed on exactly one machine.
Key structural properties of cyclic schedules are studied. A search algorithm based on these properties is proposed, and preliminary computational tests of the algorithm are reported.
TL;DR: An extension of an earlier integer programming model developed by other authors to formulate a general n-job, m-machine job-shop problem involves substantially fewer functional constraints at the expense of an increase in the number of upper bound variables.
Abstract: This paper presents an extension of an earlier integer programming model developed by other authors to formulate a general n-job, m-machine job-shop problem. The new formulation involves substantially fewer functional constraints at the expense of an increase in the number of upper bound variables. This reduction of functional constraints, together with the imposition of upper and lower bounds on the objective value, significantly reduces the computation time for solving the integer model for the job-shop scheduling problem.
TL;DR: The results support existence of a three-way interaction between the due date, release, and sequencing procedures as well as interaction between shop utilization and procedure combination.
Abstract: Depending on the techniques employed, the due date assignment, release, and sequencing procedures in job shop scheduling may depend on one another. This research investigates the effects of these interactions with a simulation model of a dynamic five-machine job shop in which early shipments are prohibited. Performance of the system is measured primarily in terms of the total cost (work-in-process cost, finished goods holding cost, and late penalty) incurred by the shop, but a number of non-cost performance measures are also reported. The results support existence of a three-way interaction between the due date, release, and sequencing procedures as well as interaction between shop utilization and procedure combination. Statistical tests are used to identify those rules that perform best both overall and in combination with other rules.
TL;DR: The use of the Kanban method is described for the control of production in a job-shop in order to reduce makespan, reduce work-in-progress, improve machine utilisation, and to control the number of machine setups.
TL;DR: It is shown that use of the open network model leads to a separable, convex formulation of the problem of workload allocation in an open Jackson network of multiserver queues, and it is proved in general that server groups with the same number of servers should be loaded equally and larger groups should beloaded more heavily than smaller groups.
Abstract: In this paper, we examine the general problem of workload allocation in an open Jackson network of multiserver queues. We show that use of the open network model leads to a separable, convex formulation of the problem with relatively simple optimality conditions. Using these conditions, we prove in general that server groups with the same number of servers should be loaded equally and larger groups should be loaded more heavily than smaller groups. It is also shown that server pooling, combining servers into larger groups, will always reduce congestion and/or increase throughput. We discuss the significance of our results for job shop applications and also for the concept of a production bottleneck. In systems with an unbalanced configuration of servers, traditional, deterministic bottleneck analysis is distinctly nonoptimal; our results provide a simple way to locate production bottlenecks in shops with significant queueing effects.
TL;DR: A heuristic algorithm to manage the remaining links between the scheduling subproblems obtained as a result of the splitting process is developed and numerical examples are given to illustrate these algorithms.
Abstract: In this paper we propose a scheduling algorithm based on splitting up the problem into separate yet linked subproblems. We develop a heuristic algorithm to manage the remaining links between the scheduling subproblems obtained as a result of the splitting process. The complexity of the computation and the performance of the algorithms are examined and numerical examples are given to illustrate these algorithms.
TL;DR: In this article, the problem of how to schedule a shop operating with both finite machine and tooling resources, and faced by varying levels of tooling-related sequence dependency in the setups, was examined.
Abstract: SUMMARY In a previous study, we began the process of examining how finite tooling resources affect the operation of a simulated job shop. The paper extends this line of research by focusing on the problem of how to schedule a shop operating with both finite machine and tooling resources, and faced by varying levels of tooling-related sequence dependency in the setups. Four tool assignment rules and two dispatching procedures are evaluated. Findings show the importance of using tool assignment rules which consider not only tool-related information such as tool availability but also the priority of the jobs waiting to be processed. Specifically, as the level of sequence dependence increases and the availability of tooling decreases, the performance of the shop is greatly influenced by the tool assignment rule used to manage the flow of tooling to and from work centres
09 Nov 1992
TL;DR: The authors present an efficient genetic algorithm called the single populated genetic algorithm (SPGA), which uses an individual in a generation and together with the representation method can realize flexible scheduling for job shop.
Abstract: The authors present an efficient genetic algorithm (GA) called the single populated genetic algorithm (SPGA). The algorithm uses an individual in a generation. Without using crossover, the solution is improved through mutations only. The algorithm is very fast in terms of convergence and the solution quality is excellent. The SPGA was applied in the traveling salesman problem (TSP) and was verified to be efficient through simulations. An application of the SPGA to the jobshop scheduling problem (JSP) is also studied. A representation method for the JSP is described. The genotype represented by the new method is simple and no illegal schedule is produced. The new genetic algorithm together with the representation method can realize flexible scheduling for job shop. >
01 Jan 1992
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TL;DR: An interactive due date management system for controlling a job shop operation that can be used interactively by a production manager to set up alternative schedules whilst allowing for different priority scheduling rules under various production capacity levels.
Abstract: This paper presents an interactive due date management system for controlling a job shop operation. The system is a simple procedure for setting attainable due dates for a job. The proposed system can be used interactively by a production manager to set up alternative schedules whilst allowing for different priority scheduling rules under various production capacity levels.
TL;DR: A multiple objective approach for the order (market) selection decision problem of industrial firms with job shop production flows is discussed, which consists of a multiple objective programming model, an interactive solution procedure, and a group decision making mechanism.
TL;DR: A Decision Support System which makes appropriate use of combinatorial optimization, knowledge-based and simulation techniques to help to solve the production scheduling problem.
Abstract: Production scheduling is part of the production planning, control and execution process, which covers everything from designing to manufacturing a product. From a planning point of view, scheduling is done on an operational and shop floor level. Most of the existing information systems for production planning, and control have great deficiencies in their scheduling parts. The main reasons for this are the inherent difficulties of the arising questions like combinatorial problem complexity and the difficulty in responding quickly to a dynamic and unpredictable job shop environment (machine breakdowns, rush orders, extra work etc.). Thus shop floor planning and control must be coupled with intelligent scheduling and brought close to the objects to be scheduled. For this purpose we have designed a Decision Support System which makes appropriate use of combinatorial optimization, knowledge-based and simulation techniques to help to solve the production scheduling problem.
17 Sep 1992
TL;DR: In this paper, a method for equipment planning is proposed for job type production systems, and computer experiment results obtained with a semiconductor fab model are given. But it is not shown that the process considered is far faster than configuring the job shops manually, and that the configuration obtained is optimum.
Abstract: A novel method for equipment planning is proposed for job type production systems, and computer experiment results obtained with a semiconductor fab model are given. The production system is modeled as an open queueing network (QN). The number of servers in the shops are then optimized by simulated annealing. The experiment demonstrated that the process considered is far faster than configuring the job shops manually, and that the configuration obtained is optimum, thus resolving the disadvantages of the traditional method. An advantage of the approach presented is that a wider range of parameter (e.g. product mix) optimization can be handled with the same combination of QN and annealing. >
TL;DR: In this article, the authors investigated the problem of accepting or rejecting arriving jobs to a job shop in which the flow times of jobs are stochastic and provided the decision maker with a helpful managerial tool in negotiating the due date, earliest delivery date, and penalty cost with the customer so as to maximize the expected net profit.
TL;DR: In this paper, a paradigm for the time-managed control of material flow in job shop and small-lot environments which are subject to random disruptions is presented, implemented through a model which invokes certain special structures to investigate fundamental operating characteristics, including measures of kitting effectiveness.
Abstract: A paradigm for the time-managed control of material flow in job shop and small-lot environments which are subject to random disruptions is presented. The paradigm is implemented through a model which invokes certain special structures to investigate fundamental operating characteristics, including measures of kitting effectiveness. It is proven that schedules are most economically time-managed by co-ordinating vendor deliveries, rather than by deliberately delaying materials in-process. Fundamental results which permit scheduling and rescheduling are derived, along with certain performance measures necessary to time-managing flow effectively. Numerical tests indicate the accuracy of the model and demonstrate how material flows can be time-managed to minimize costs. The paradigm appears to be better suited than others for managing material flows in job shop and small-lot environments.
TL;DR: In this article, a simulation-based scheduler based on SIMAN (a general purpose simulation package) is presented as the means for generating schedules in a modern CNC job shop.
TL;DR: Scheduling Assistant is developed, an interactive prototype knowledgebased MMS written in VAX OPS5 that displays a methodology for knowledgebased job shop scheduling decision support that makes the search for expert scheduling knowledge easier, efficient, and more accessible to the practitioner user.
Abstract: The problem of job shop scheduling, requires satisfaction of diverse and conflicting constraints. A large body of scheduling algorithms exists. The search for an appropriate algorithm or model can be very frustrating as well as discouraging for the prospective user, due to the complexity and the costs involved. Expert help may not always be affordable or accessible at the right moment. Knowledgebased Model Management Systems (MMS) enable us to make the expertise more accessible and affordable. In this paper we develop Scheduling Assistant, an interactive prototype knowledgebased MMS written in VAX OPS5 that displays a methodology for knowledgebased job shop scheduling decision support. It makes the search for expert scheduling knowledge easier, efficient, and more accessible to the practitioner user.
TL;DR: The ibis commitment as discussed by the authors is dedicated support of the total quality process, which means an enlightened adherence to a participative style of management and willingness to provide the necessary training, which sets a compass course for the journey, though not a specific destination.
Abstract: With increasing competition from overseas producers, it is becoming increasingly clear that the only way for high-wage nations like the United States to succeed is by producing quality products. To boost performance, organizations must implement a total quality process by reducing their bureaucracy and giving more authority to workers. Never-ending and all-encompassing, the road to the implementation of quality service depends on senior management commitment, which sets a compass course for the journey, though not a specific destination. The essence of ibis commitment is dedicated support of the total quality process, which means an enlightened adherence to a participative style of management and willingness to provide the necessary training. This article presents a case study of a job shop's progress along this road.
01 Jan 1992
TL;DR: This work proposes a methodology for scheduling semiconductor test operations and presents algorithms to minimize maximum lateness and number of tardy jobs on testers and batch processing machines.
Abstract: We propose a methodology for scheduling semiconductor test operations. While current practice in industry is based on dispatching rules, our methodology takes a more global approach. The facility or job shop is decomposed into a number of workcenters. The methodology proceeds by sequencing one workcenter at a time. A disjunctive graph representation of the facility is used to model the interactions of the workcenters. We present algorithms to minimize maximum lateness and number of tardy jobs on testers and batch processing machines. The overall methodology has been implemented on a set of problems based on a real industry setting.