Showing papers on "Flow shop scheduling published in 1985"
TL;DR: The authors present a scheduling algorithm which works dynamically and on loosely coupled distributed systems for tasks with hard real-time constraints; i.e., the tasks must meet their deadlines.
Abstract: Most systems which are required to operate under severe real-time constraints assume that all tasks and their characteristics are known a priori. Scheduling of such tasks can be done statistically. Further, scheduling algorithms operating under such conditions are usually limited to multiprocessor configurations. The authors present a scheduling algorithm which works dynamically and on loosely coupled distributed systems for tasks with hard real-time constraints; i.e., the tasks must meet their deadlines. It uses a scheduling component local to every node and a distributed scheduling scheme which is specifically suited to hard real-time constraints and other timing considerations. Periodic tasks, nonperiodic tasks, scheduling overheads, communication overheads due to scheduling and preemption are all accounted for in the algorithm. Simulation studies are used to evaluate the performance of the algorithm.
180 citations
TL;DR: Application of heuristic solution procedures to the resource-constrained, multi-project scheduling problem is analyzed under equal and unequal penalties and it is shown that the choice of a scheduling rule can be based upon the resource, problem size, and penalty.
Abstract: Application of heuristic solution procedures to the resource-constrained, multi-project scheduling problem is analyzed under equal and unequal penalties. The performance of ten scheduling rules is categorized with respect to four project summary measures, namely, resource-constrainedness, location of the peak requirements, and problem size. It is shown that the choice of a scheduling rule can be based upon the resource-constrainedness, problem size, and penalty. These results are based on scheduling, in detail, over 3000 multi-project scheduling problems, each containing three projects and from 24 to 66 activities.
149 citations
TL;DR: A special property of proportionate flowshops, namely that the bottleneck in the shop is almost always the one where job operations are proportionately longer than for any other operations (the slowest machine), is used to demonstrate a scheduling procedure that makes scheduling decisions by focusing on the information and consequences at the bottleneck resource, called the Focused Approach.
Abstract: The proportionate flowshop is a special class of flowshops in which the operation times of jobs are proportionate, e.g., because of differences in the speeds of machines. In this paper, we make use of a special property of proportionate flowshops, namely that the bottleneck in the shop is almost always the one where job operations are proportionately longer than for any other operations (the slowest machine) to demonstrate a scheduling procedure that makes scheduling decisions by focusing on the information and consequences at the bottleneck resource. This is called the Focused Approach. The scheduling objective is to minimize the total tardiness cost of jobs, where each job may have a different tardiness cost. The decision rule used in this approach is the Idle Time Rule whose development is described in this paper. The approach was tested using approximately proportionate flowshops of different sizes. The results obtained for small 3-machine problems were compared against the optimal permutation schedul...
110 citations
TL;DR: A family of algorithms is described for finding optimum schedules for job-shops that are of a branch and bound type but have a complete schedule associated with each node of the search tree.
Abstract: A family of algorithms is described for finding optimum schedules for job-shops. The algorithms are of a branch and bound type but have a complete schedule associated with each node of the search tree. Branching from nodes is based on important conflicts in the schedule. Some results are provided.
82 citations
TL;DR: In this article, the effects of various labor assignment rules on the shop's performance were examined in a dual-constrained job shop and the results showed that none of the eleven rules had a significant impact on shop performance.
74 citations
TL;DR: 11 sequencing rules (some of which are common to simple job shops and some decigned specifically for assembly shops) are evaluated using a simulation analysis of a hypothetical assembly shop using an ANOVA procedure.
Abstract: Research relating to sequencing rules in simple job shops has proliferated, but there has not been a corresponding proliferation of research evaluating similar sequencing rules in more complex assembly job shops. In a simple job shop, all operations are performed serially; but an assembly shop encompasses both serial and parallel operations. As a result of the increased complexity of assembly shops, the results associated with the performance of sequencing rules in simple job shops cannot be expected for an assembly shop. In this paper, 11 sequencing rules (some of which are common to simple job shops and some decigned specifically for assembly shops) are evaluated using a simulation analysis of a hypothetical assembly shop. The simulation results are analyzed using an ANOVA procedure that identifies significant differences in the results of several performance measures. Sensitivity analysis also is performed to determine the effect of job structure on the performance of the sequencing rules.
56 citations
01 Apr 1985
TL;DR: Cyclo-static processor solutions overcome the weaknesses of systolic processors and of SSIMD and PSSIMD solutions for the class of algorithms that can be described by cyclic shift-invariant flow graphs.
Abstract: Cyclo-static processor solutions overcome the weaknesses of systolic processors and of SSIMD and PSSIMD solutions for the class of algorithms that can be described by cyclic shift-invariant flow graphs. Cyclo-static solutions are a broad family of processor (efficiency) optimal, synchronous, multiprocessor realizations that by appropriate design choices can be rate optimal, input-output delay optimal and communications optimal. For a given algorithm the cyclo-static family of solutions contains many classes which includes SSIMD and PSSIMD solutions as special cases, when they exist.
46 citations
TL;DR: In this article, the authors considered the two-machine flow shop problem, where each job becomes available for processing at its release date after which it must be processed without preemption on the first machine and then on the second machine.
Abstract: The two-machine flow-shop problem is considered in which each job becomes available for processing at its release date after which it must be processed without preemption on the first machine and then on the second machine. The objective is to minimize the maximum completion time. Three heuristics are presented which each have a worst-case performance ratio of 2. One of these is modified to give an improved worst-case performance ratio of 5/3.
44 citations
TL;DR: This paper considers a two-machine shop scheduling problem consisting of two disjoint job subsets F and O, and gives the optimal algorithm for the nontrivial case.
39 citations
TL;DR: This paper studies the impact of job routing pattern on the performance of dual resource constrained (DRC) systems and concludes that routing pattern has no significant impact on the relative effectiveness of various dispatching rules.
Abstract: This paper studies the impact of job routing pattern on the performance of dual resource constrained (DRC) systems. Three markedly different job routing patterns are simulated using a DRC system model that incorporates labor transfer times. The problem is viewed from two perspectives: one portion of the analysis focuses on the relative performances of five different dispatching rules as the routing pattern varies; the other examines the effect of the routing pattern on each rule's individual performance. One generalized conclusion of this study is that routing pattern has no significant impact on the relative effectiveness of various dispatching rules. Consequently, findings from pure job-shop research studies may be applied to situations where a mixture of job-shop and flow-shop routings is present.
TL;DR: In this paper, an approach to the job shop sequencing problem by determining the priority of a job from a linear combination of the basic quantities of operation times and due dates is presented.
Abstract: This paper sets out, an approach to the job shop sequencing problem by determining the priority of a job from a linear combination of the basic quantities of operation times and due date. This achieves a simple yet unified format. Furthermore, since these basic quantities are used in fixed linear combinations in the majority of well-known simple heuristics, the rule outlined in the paper is capable of representing such heuristics as special cases within its framework. A performance function is used to assess the effectiveness of the rule and no limitations are imposed on its structure. The form of the variable priority rule is then determined by a computer search routine basing its decisions on the values of the performance function. This overall approach to job shop sequencing we term the search sequencing rule (SSR).
TL;DR: In this article, the effects of using various priority scheduling rules for capacity management and shop floor control in an MRP production system were investigated and the results showed that the application of different priority rules does cause such a system to perform differently.
Abstract: This paper concerns a study of the effects of using various priority scheduling rules for capacity management and shop floor control in an MRP production system. The results of the study show that the application of different priority rules does cause such a system to perform differently. The indications are that a practitioner could cause his MRP system to perform in a more desirable fashion by his choice of priority scheduling rules for shop floor control under various capacity levels.
TL;DR: In this article, the authors evaluate scheduling policies for the production of assembled products in an assembly shop using a simulation model of a dual constrained assembly shop operation and an ANOVA procedure to statistically determine whether job structure, duedate assignment rule, labor assignment rule and item sequencing rule or their interaction significantly affect the root mean square of tardiness of jobs completed by the assembly shop.
Abstract: The purpose of this paper is to evaluate scheduling policies for the production of assembled products in an assembly shop. The scheduling policies examined include duedate assignment, labor assignment and item sequencing rules. The sensitivity of these rules to product structure is also considered. The data for analysis is generated by a SLAM II simulation model of a hypothetical dual constrained assembly shop operation. The 2·3·3·3 complete factorial experiment is analyzed by an ANOVA procedure to statistically determine whether job structure, duedate assignment rule, labor assignment rule and item sequencing rule or their interaction significantly affect the root mean square of tardiness of jobs completed by the assembly shop. Further analysis to identify where significant differences in performance occurs is conducted via Tukey multiple comparison tests and general linear contrasts.
TL;DR: The problem of preemptively scheduling a set of n independent jobs on an m-machine open shop is studied, and it is indicated that constructing optimal flow-time schedules is NP-hard for m larger than two.
TL;DR: A probabilistic analysis is presented for this NP-hard problem known as 1/rj/ΣCj in the scheduling literature and it is shown that the problem can be broken into 2 categories: the undersaturated and the oversaturated case.
Abstract: There are n jobs that have to be processed on one available machine. The ith job arrives at epoch r1 and it takes P1 units of time to carry out its operation. No preemptions are allowed. It is desired to minimize total flow time. A probabilistic analysis is presented for this NP-hard problem known as 1/rj/ΣCj in the scheduling literature. Under very general probability distributions of the problem data, it is shown that the problem can be broken into 2 categories: the undersaturated and the oversaturated case. Asymptotically optimal algorithms are presented for each case.
TL;DR: In a flow shop where the machine speeds increase from the first to last machine and the workload distributions are ordered by a likelihood ratio criterion, then the makespan of the jobs is stochastically minimized by processing the jobs in the order of least to greatest (greatest to least) workload.
Abstract: We consider stochastic models for flow shops, job shops and open shops in which the work required by job j is the same at each machine, being a random variable Wj. Because machines operate at different speeds, Si, the processing time of job j at machine i is Wj/Si,. It is the main result of this note that in a flow shop where the machine speeds increase (decrease) from the first to last machine and the workload distributions are ordered by a likelihood ratio criterion, then the makespan of the jobs is stochastically minimized by processing the jobs in the order of least to greatest (greatest to least) workload.
01 Mar 1985
TL;DR: Two very different distributed scheduling algorithms which contain explicit mechanisms for stability are presented and evaluated and indicate how very specific the treatment of stability is to the algorithm and environnent under consideration.
Abstract: Many distributed scheduling algorithms have been developed and reported in the current literature. However, very few of them explicitly treat stability issues. This paper first discusses stability issues for distributed scheduling algorithms in general terms. Two very different distributed scheduling algorithms which contain explicit mechanisms for stability are then presented and evaluated with respect to individual specific stability issues. One of the agorithms is based on stochastic learning automata and the other on bidding. The results indicate how very specific the treatment of stability is to the algorithm and environnent under consideration.
01 Jan 1985
TL;DR: This paper provides an update to an earlier description of the HASTUS algorithm and describes improvements which have already been implemented (e.g. the marching algorithm) and other improvements still under research and development.
Abstract: This paper provides an update to an earlier description of the HASTUS algorithm. It describes improvements which have already been implemented (e.g. the marching algorithm) and other improvements still under research and development.
TL;DR: In this article, the effectiveness of composite time/cost priority-scheduling rules on both time and cost performance measures is explored, at various shop-utilization levels, against standard and modified time-based rules such as critical ratio and shortest processing time.
Abstract: This paper explores the effectiveness of composite time/cost priority-scheduling rules on both time and cost performance measures. These dispatching rules, based on value added or profitability, are compared, at various shop-utilization levels, against standard and modified time-based rules such as critical ratio and shortest processing time. The simulation of a randomly routed job shop shows that work in process can be significantly reduced with varying sacrifices in time-performance measures. At moderate levels of utilization, the results suggest that these dollar-based rules perform quite well. Both tabular and graphic, results are shown to clarify the tradeoffs which result.
01 Jan 1985
TL;DR: Two programs for bus crew scheduling are described, one of which is fully automatic, based on a mathematical programming formulation, and is about to be adopted by a major transport undertaking, and the other is interactive, incorporating heuristics developed in an earlier automatic program.
Abstract: Two programs for bus crew scheduling are described. One is fully automatic, is based on a mathematical programming formulation, and is about to be adopted by a major transport undertaking. The other is interactive, incorporating heuristics developed in an earlier automatic program, and is currently undergoing trials with a number of organizations. The background to these complementary developments is outlined, and each of the programs is described.
TL;DR: In this article, a network simulation model that integrates the MRP-based shop control level with the shop level in a manufacturing system is described and its usage demonstrated within the context of a realistic shop scenario that encompasses multiple-level product structures, several-component items, job and assembly operations, machine setups and backordering.
Abstract: Despite the increased attention recently to material requirements planning (MRP) in the research literature. MRP has frequently proved to be unsuccessful on actual implementation. One factor related to its unsuccessful implementation is that MRP systems are often not sufficiently analysed and tested within an actual shop scenario prior to implementation. In this paper, a network simulation model that integrates the MRP-based shop control level with the shop level in a manufacturing system is described, and its usage demonstrated within the context of a realistic shop scenario that encompasses multiple-level product structures, several-component items, job and assembly operations, machine setups and backordering. Five simulation experiments are conducted using the network simulation model, including cases in which: (1) all model parameters are constant (standard case), (2) product demand is varied, (3) set-up times are varied, (4) processing times are variable and (5) the worst cases from all the previous ...
01 Jan 1985
TL;DR: This article introduces a general iterative decomposition algorithm for permutation scheduling problems and applies it to the permutation flow shop scheduling problem, and develops bounds needed and two heuristic algorithms based on the iteratives decomposition approach.
TL;DR: A zero-one integer programming model for the job shop scheduling problem with minimum makespan criterion is presented in this article, which consists of two parts: (a) a branch and bound parametric linear programming code for solving the problem with fixed completion time; (b) a problem expanding algorithm for finding the optimal completion time.
Abstract: A new zero-one integer programming model for the job shop scheduling problem with minimum makespan criterion is presented. The algorithm consists of two parts: (a) a branch and bound parametric linear programming code for solving the job shop problem with fixed completion time; (b) a problem expanding algorithm for finding the optimal completion time. Computational experience for problems having up to thirty-six operations is presented. The largest problem solved was limited by memory space, not computation time. Efforts are under way to improve the efficiency of the algorithm and to reduce its memory requirements.
TL;DR: In this paper, the operating characteristics of the total-work-content (TWK) due-date assignment method in a dynamic job shop were studied and an analytical procedure was presented to derive the optimal solution and to show that k ∗ p is a unique absolute minimum point of the strictly convex cost functions included in the cost model.
Abstract: The paper studies the operating characteristics of the total-work-content (TWK) due-date assignment method in a dynamic job shop. The due-date for each job is established by adding a multiple of the job's total processing-time to its arrival time at the shop. It is assumed that there will be penalty costs if the shop quotes excessively long due-dates compared with its competitors' and cannot complete the jobs exactly on their assigned due-dates. A cost model composed of these two opportunity cost components is used. The objective is to find the optimal processing-time multiple k ∗ p that will minimize the expected total cost per job. An analytical procedure is presented to derive the optimal solution and to show that k ∗ p is a unique absolute minimum point of the strictly convex cost functions included in the cost model. It is also shown that determination of the optimal processing-time multiple requires only information readily accessible in the shop. Under certain circumstances, k ∗ p can even be exclu...
01 Jan 1985
TL;DR: In this article, two bipartite matching problems arising in Vehicle Scheduling are considered: the capacitated matching and the multicommodity matching, and a heuristic algorithm based on Lagrangean relaxation is presented together with experimental results.
Abstract: Two bipartite matching problems arising in Vehicle Scheduling are considered: the capacitated matching and the multicommodity matching. For the former, given a reasonable cost structure, we can exhibit a polynomial time algorithm, while the general case is conjectured to be NP-hard. The latter problem is shown to be NP-hard. A heuristic algorithm based on Lagrangean relaxation for the capacitated version of the multicommodity matching is also presented together with experimental results.
01 Jan 1985
TL;DR: A model has been constructed which enables a component manufacturing shop to be interactively defined at a V.D.U., and used to calculate the average job makespan under a variety of assumptions relating to work content, capacity and operational procedures.
Abstract: A model has been constructed which enables a component manufacturing shop to be interactively defined at a V.D.U., and used to calculate the average job makespan (time taken on the shop) under a variety of assumptions relating to work content, capacity and operational procedures. A second phase of the model allows the production controller to define a scheduling technique and lead-time assignment method, and provides guidance on how the makespan should be converted to lead times (time allowed on the shop). The model uses a mixture of queueing theory and simulation. This paper principally describes the methodology, but uses of the model are briefly discussed.