Showing papers on "Job shop published in 1982"
Book•
24 Mar 1982
TL;DR: In this article, an introduction to the mathematics of the job shop is presented, with a focus on the sequential and scheduling aspects of the system. But this approach is not suitable for all job-shop scenarios.
Abstract: (1982). Sequencing and Scheduling: An Introduction to the Mathematics of the Job-Shop. Journal of the Operational Research Society: Vol. 33, No. 9, pp. 862-862.
1,017 citations
TL;DR: A review of the state of the art in the study of dispatching rules can be found in this paper, where a dispatching rule is used to select the next job to be processed from a set of jobs awaiting service.
Abstract: This paper reviews recent studies of dispatching rules. A dispatching rule is used to select the next job to be processed from a set of jobs awaiting service. The paper has two objectives. The first is to discuss the state of the art in the study of dispatching rules. The discussion includes analytical approaches, simulation techniques and evaluation criteria. The second objective of the paper is to compare several of the dispatching rules listed in the Appendix using the results of recently published studies. It is impossible to identify any single rule as the best in all circumstances. However, several rules have been identified as exhibiting good performance in general.
967 citations
TL;DR: A major facility for manufacturing research is being established at the National Bureau of Standards (NBS) as discussed by the authors, which is designed to provide extreme flexibility and to be capable of emulating a wide variety of manufacturing cells typical of a small machine job shop.
229 citations
TL;DR: The results indicate that operation due dates improve every conventional measure of job shop performance.
131 citations
TL;DR: A systematic analysis of shop performance versus different scheduling rules is presented using a computer simulation model of a conventional job shop as a basis and produced some interesting anticipated as well as unanticipated results.
63 citations
TL;DR: It is shown that the problem of constructing optimal mean finishing time preemptive and nonpreemptive schedules is NP-hard, even when all nonzero tasks have identical execution time requirements.
Abstract: The problem of preemptively and nonpreemptively scheduling a set of n independent jobs on an m machine open shop, flow shop or job shop is studied. It is shown that the problem of constructing optimal mean finishing time preemptive and nonpreemptive schedules is NP-hard. These problems are not only NP-hard in the strong sense, but remain NP-hard even when all nonzero tasks have identical execution time requirements. These results will also apply to the case when the problem is to construct an optimal finish time preemptive and nonpreemptive schedule for a flow shop or a job shop. We also discuss the problem of constructing no-wait schedules for these problems.
57 citations
TL;DR: A mathematical model based on the branch-and-bound technique to solve static scheduling problems involving n jobs and m machines where the objective is to minimize the cost of setting up the machines is presented.
Abstract: This paper presents a mathematical model based on the branch-and-bound technique to solve static scheduling problems involving n jobs and m machines where the objective is to minimize the cost of setting up the machines. Set-up times are sequence dependent and not included in processing times. There is a finite non-zero cost associated with setting the machines which is different for each machine. It is further assumed that the routing may be different for different jobs and a job may return to a machine more than once.
56 citations
TL;DR: In this paper, a simple production system capable of producing many different products is examined by decomposing the problem into its major parts (carousel, work transporter, linking conveyors and the work stations) and then using the results to compute overall system performance.
Abstract: The extreme cases of production operations—the job shop and the progressive assembly line—are viewed as special cases of a single general production model. They differ only in time span and the number of possible production routes. The common elements of the extreme systems can be studied by analysing a recent production system innovation, the carousel-work-transporter system. In this paper a simple production system capable of producing many different products is examined by decomposing the problem into its major parts (carousel, work transporter, linking conveyors and the work stations) and then using the results to compute overall system performance. We introduce the concept of virtual inventory and show how systems with this property can be more productive than progressive storage systems. While the system can be analysed by using computer simulation models we use only analytic queue theory models to obtain approximate results.
42 citations
TL;DR: In this paper, a modified approach to scheduling within a GT cell that implicitly takes advantage of common setups and part family coding structures is presented, where the GT cell environment is examined from a scheduling perspective in relation to a job and flow shop.
31 citations
TL;DR: In this article, a procedure is introduced in which selected jobs, initially programmed in a schedule at maximum production rates, hare their machining rates reviewed in order to reduce costs.
Abstract: Two alternative objectives when analysing machining rates are to produce components at maximum production rate or at minimum cost. Tn this psiper, a procedure is introduced in which selected jobs, initially programmed in a schedule at maximum production rates, hare their machining rates reviewed in order to reduce costs. An integrated manufacturing system with a job shop work pattern is assumed and in which due date criteria are applied to finished jobs. The cost reduction procedure is designed to operate while maintaining the original schedule performance.
18 citations
TL;DR: In this paper, the problem of maximizing the long-run average return (reward rate) was formulated as two special semi-Markov decision processes and discussed a class of the control problem of stochastic production systems.
Abstract: Consider job-shop production under the conditions that orders arrive according to a Poisson process, processing time is dependent on the reward of the orders, production capacity is finite, and backlog is allowed. This paper distinguishes two simple order selection policies with a selection criterion (control variable), formulates the problem of maximizing the long-run average return (reward rate) as two special semi-Markov decision processes, and discusses a class of the control problem of stochastic production systems. By a numerical example, it is concluded that two simple policies: Static Selection Policy (SSP) and Sequential Selection Policy (SeSP) are alternative.
TL;DR: In this paper, a queueing network technique (Solberg's CAN-Q) and a flow control simulator (SINDECS) are applied to investigate general, fundamental performance properties of material flow systems (MFS).
Abstract: A queueing network technique (Solberg's CAN-Q) and a flow control simulator (SINDECS) are applied to investigate general, fundamental performance properties of material flow systems (MFS). The effects of a system's structure and flow logic on performance are compared for three typical flow systems: transfer line, recirculating conveyor loop, and job shop. The concepts of Most Economical MFS for a given performance level, Iso-Performance MTS combinations, and Overall MFS Configuration Measures are introduced.
TL;DR: This study investigates the behavior of a job shop depicted as an integral component of a firm and suggests that conventional open-loop job shop studies tend to neglect important interactions with factors external to the shop itself.
TL;DR: A network modelling approach to the difficult and complex task of estimating job flow-times not previously presented in the literature is presented.
Abstract: One of the most important aspects of job shop planning is the contract negotiation process. In this process the job shop vendor must negotiate a job due-date acceptable to both job shop and the customer. Failure to obtain reasonably accurate predictions of the job completion time can result in penalties and/or lost future sales for the job shop. As such, estimation of job flow-times is critical to successful job shop operation. This paper presents a network modelling approach to the difficult and complex task of estimating job flow-times not previously presented in the literature. The approach is demonstrated via a case example where the system model is developed as a Q-GERT network and simulation results are obtained.
TL;DR: In this article, the authors define batch or job shop production and review the functions of production planning and production control in a job shop manufacturing situation, arguing that the separation of planning and control has resulted in the artificial isolation of the sequencing problem in job shop research.
Book•
01 Jan 1982
TL;DR: Simulations comparing work center control rules to the critical ratio rule for job dispatching indicate that work centers control can increase performance to customer due date while simultaneously reducing average work in process inventory.
01 Jan 1982
TL;DR: The paper describes the Philosophy followed and the procedure adopted for the design of a mini computer based Interactive, Real Time Job Shop Control System.
Abstract: The paper describes the Philosophy followed and the procedure adopted for the design of a mini computer based Interactive, Real Time Job Shop Control System.
TL;DR: A brief history of job shops since the caveman era is surveyed, and the essential elements of a job shop are found to be: to earn your living performing a useful service, or creating a useful object, for your contemporaries.
Abstract: A brief history of job shops since the caveman era is surveyed, and the essential elements of a job shop are found to be: to earn your living performing a useful service, or creating a useful object, for your contemporaries. The complexities of setting up a computer job shop are described. Inspection of a symbolic floor plan of the shop shows a Program Development, Installation, and Repair Lab that operates with the well-known pitfalls and traps that occur when a real live person interacts with a large, stupid computer. The Output Assembly and Analysis Lab is the holding area where up to N projects are worked on simultaneously. On the main floor of the shop resides the program load modules, some of which are described in detail. Separate from the main shop area is the Remote Job Entry Lab, affectionately called the Physics Group Zoo. The creatures that dwell there are also described to illustrate the difficulty in data preparation and job submission. In spite of all these adversities, the thrill of solving complex problems makes it all worthwhile.
14 Jun 1982
TL;DR: This work investigated management of an automated job shop with an unpredictable job stream and randomly failing machines, and devised a system based on dynamic allocation of machines to jobs under a distributed data flow control architecture that reduced sensitivity to machine failures, and simplified shop expansion.
Abstract: We investigated management of an automated job shop with an unpredictable job stream and randomly failing machines. The shop used automated materials handling to move jobs between automated machines, so that entering and removing jobs were the only manual operations, excluding maintenance and repair. The stochastic nature of the shop precluded a traditional scheduling approach. We devised a system based on dynamic allocation of machines to jobs under a distributed data flow control architecture. The data flow architecture reduced sensitivity to machine failures, and simplified dynamic allocation. It also simplified shop expansion. Unexpectedly, machine utilizations exceeded 93% for machine failure rates below 16% in a simulated shop with machine and job stream characteristics typical of contemporary Computer-integrated Manufacturing Systems (CMS). For this typical job shop, dynamic allocation produced utilizations comparable to those expected from scheduling. Machine utilization in contemporary job shops seldom exceeds 70%. Our paper describes the architecture and the experiments, and speculates on reasons for the high utilizations.