Showing papers on "Job shop published in 1989"
TL;DR: In this paper, a branch and bound method for solving the job-shop problem is proposed, which is based on one-machine scheduling problems and is made more efficient by several propositions which limit the search tree by using immediate selections.
Abstract: In this paper, we propose a branch and bound method for solving the job-shop problem. It is based on one-machine scheduling problems and is made more efficient by several propositions which limit the search tree by using immediate selections.
It solved for the first time the famous 10 × 10 job-shop problem proposed by Muth and Thompson in 1963.
836 citations
TL;DR: A critical review of a particular segment of scheduling research in which the due to date assignment decision is of primary interest is presented, observing that while the static single- machine problem with constant or common due dates has been well researched, very little or no work has been done on the dynamic multi-machine problem with sophisticated due date assignment methods.
498 citations
TL;DR: It is shown in particular that, given any desired product mix, it is possible to start the system with enough jobs in process so that some machines will be fully utilized in steady-state and the productivity is optimal.
Abstract: Timed event-graphs, a special class of timed Petri nets, are used for modelling and analyzing job-shop systems. The modelling allows the steady-state performance of the system to be evaluated under a deterministic and cyclic production process. Given any fixed processing times, the productivity (i.e., production rate) of the system can be determined from the initial state. It is shown in particular that, given any desired product mix, it is possible to start the system with enough jobs in process so that some machines will be fully utilized in steady-state. These machines are called bottleneck machines, since they limit the throughput of the system. In that case, the system works at the maximal rate and the productivity is optimal. The minimal number of jobs in process allowing optimal functioning of the system is further specified as an integer linear programming problem. An efficient heuristic algorithm is developed to obtain a near-optimal solution. >
318 citations
TL;DR: Machinist as mentioned in this paper is an expert system that automatically makes process plans for fabricating metal parts on a CNC machine tool and is part of an overall effort to automate the job shop.
104 citations
TL;DR: Results presented using statistical and graphical analysis show that there is no statistically significant difference in the performance using finite loading and infinite loading release mechanisms, and succeeding increases in labor flexibility show a diminishing return in shop performance.
90 citations
TL;DR: An efficient algorithm is described and analyzed for minimizing the total flow time of the products in a single machine job shop in which subassemblies of two different types are made and then assembled into products.
Abstract: We consider a single machine job shop in which subassemblies of two different types are made and then assembled into products The time required for each type is known A fixed changeover cost is incurred whenever the machine is switched over from one type to the other We describe and analyze an efficient algorithm for minimizing the total flow time of the products Applications to the automated manufacture of circuit boards are noted
82 citations
TL;DR: In this article, the authors study job-scheduling methods for flexible manufacturing systems (FMSs) and show that routeing flexibility is a feature that distinguishes FMS scheduling from a classic general job shop problem.
Abstract: In this paper, we study job-scheduling methods for flexible manufacturing systems (FMSs). Routeing flexibility is a feature that distinguishes FMS scheduling from a classic general jobshop problem....
81 citations
TL;DR: In this paper, the authors examined the effect of three different product structures on the performance of selected priority dispatching rules in a six-machine assembly job shop and found that significant relationships exist between the structure of the product bill of materials and the prioritization rule, and that specific rules are indeed better suited to certain product structures.
Abstract: SUMMARY Single-stage job-shop scheduling has received a great deal of attention in the published literature. Significantly less research has been done in the area of assembly job shops. With the onslaught of MRP implementations designed to plan and control assembly job shops, practitioners have been confronted head-on with the need to improve dispatching procedures. This paper examines the effect of three different product structures on the performance of selected priority dispatching rules in a six-machine assembly job shop. Results indicate that significant relationships exist between the structure of the product bill of materials and the priority dispatching rule, and that specific rules are indeed better suited to certain product structures.
72 citations
TL;DR: Four release mechanisms are tested in conjunction with two dynamic, due date oriented dispatching rules, Modified Operation Due Date and Critical Ratio to simulate the job shop performance.
Abstract: One of the basic assumptions in past job shop research is that arriving jobs are immediately released to the shop floor for processing regardless of available job and shop information. In practice, jobs arriving at the shop are usually collected into a backlog file. Jobs are then released by some mechanism so that they can be processed within the time available before the due date. This study examines the effects of several release mechanisms on the performance of a dual resource constrained job shop. The release mechanisms differ in the amount and types of information used to make release decisions. Four release mechanisms are tested in conjunction with two dynamic, due date oriented dispatching rules, Modified Operation Due Date and Critical Ratio. The job shop environment is specified by two levels of due date tightness. A labor and machine limited job shop model was used to simulate the shop performance.
53 citations
TL;DR: In this paper, job characteristics and shop characteristics are investigated to determine which has a greater impact on predicting job flowtimes, which is accomplished by determining which characteristic most greatly influences the deviation of planned job lead times from actual job flow times.
Abstract: In a Materials Requirements Planning (MRP) system, component lead times are generally assumed to be known and constant. Since a requirement of a MRP system is that components finish on time, slack is often built into component lead times to insure that actual job flowtimes equal planned job lead times. In this study, job characteristics and shop characteristics are investigated to determine which has a greater impact on predicting job flowtimes. This is accomplished by determining which characteristic most greatly influences the deviation of planned job lead times from actual job flowtimes. After identifying those factors which have the greatest influence on the job's flowtime, due date assignment rules are developed. A simulation study is then made to determine. which of the due date assignment rules perform best for varying product structures, as defined by various Bills of Materials (BOMs), and various shop conditions. Simulation test results are presented and discussed.
44 citations
TL;DR: In this article, a discrete release model is proposed to deal with both the static and dynamic scheduling problems in a job shop environment, which considers the routing, loading, and release decisions as well as the customary sequencing decision.
Abstract: The scheduling literature has developed two almost mutually exclusive problems; a static and a dynamic scheduling problem. The result has been that different tools have been developed to solve each problem. In this research, a model is developed such that it contains elements of both the static and the dynamic problems. This model, called here the discrete release model, considers the routing, loading, and release decisions as well as the customary sequencing decision evident in most job shop research. The objective of the research is to implement a method for examining tentative loading assignments prior to their release to the shop floor. The research develops a single pass, sequential routing and loading system. A heuristic is then developed that will enable jobs to be reloaded and rerouted prior to their start of processing. The system is tested in various shop environments to ascertain the effectiveness of this loading heuristic.
TL;DR: It is shown that the performance of different dispatching rules does indeed depend upon the degree of workload imbalance, and that a job shop or automated manufacturing system would likely benefit from implementing optimal-seeking scheduling rules instead of the traditional job dispatch rules.
TL;DR: In this article, the authors compare two well-known methods for setting manufacturing lead times (flow allowances) in a general job shop when early shipment of completed jobs is forbidden, using a computer simulation of an 8-machine job shop.
Abstract: SUMMARY The authors compare two well-known methods for setting manufacturing lead times (flow allowances) in a general job shop when early shipment of completed jobs is forbidden. One of the methods for setting a job's allowance is to make it proportional to the total processing time for the job. This method, referred to as TWK., is compared to a second method PPW. With the PPW method, a job's allowance is obtained by adding to the total job-processing time an allowance for waiting that is proportional to the number of operations that the job requires. The two allowance methods are compared using a computer simulation of an 8-machine job shop. The model is unique in that jobs are not permitted to leave the shop early. This feature of forbidding early shipment (FES) complicates the comparison between allowance methods because it draws the issue of finished-order inventory management into the analysis. Results of computer simulations over a wide range of average due-date difficulty suggest that TWK is the d...
22 May 1989
TL;DR: The proposed approach starts with the division of the facility or job shop into a number of workcenters, and a disjunctive graph representation of the entire facility is used to capture interactions between workCenters.
Abstract: The operations in the facility under study are characterized by a broad product mix, variable lot sizes and yields, long and variable setup times, and limited test equipment capacity. The assignment of products to testers varies depending on device and package type as well as temperature. The proposed approach starts with the division of the facility or job shop into a number of workcenters. The workcenters are then sequenced one workcenter at a time. A disjunctive graph representation of the entire facility is used to capture interactions between workcenters. The introduction of different management objectives leads to different workcenter problems and different production scheduling algorithms. Algorithms for two different workcenter problems are presented. Directions for future research are also discussed. >
TL;DR: In this article, an O(n 5 N )-approximation algorithm was proposed for the n -job problem, where N is the total number of tasks of all jobs.
TL;DR: In this article, the authors examined the performance of fourteen due-date oriented sequencing rules in a simulated ten-machine multistage job shop having one assembly work center, and evaluated the sensitivity of the sequencing rules and progress milestones to the complexity of product structure.
01 Nov 1989
TL;DR: In this article, a simulation study of the performance of a job shop where the equipment is subject to failure is presented, where the authors evaluate the effectiveness of some maintenance scheduling techniques under conditions involving shop load, job sequencing rule, preventive maintenance policy and maintenance capacity.
Abstract: This paper presents a simulation study of the performance of a job shop, where the equipment is subject to failure. We evaluate the effectiveness of some maintenance scheduling techniques under conditions involving shop load, job sequencing rule, preventive maintenance policy and maintenance capacity.
TL;DR: The results suggest that priority rules that utilize monetary information about jobs yield a higher NPV than many time-based rules in most situations, with little sacrifice in job tardiness.
Abstract: While the majority of the literature on shop scheduling has emphasized time-based performance criteria such as mean flow time, lateness, and tardiness, the primary goal of management should be the maximization of shop profitability. In this research the net present value (NPV) criterion is introduced to measure shop profitability. This measure combines aspects of job flow time and inventory holding costs into a single measure. A simulation model of a job shop is used to examine the performance of a variety of time- and value-based scheduling rules. These rules are evaluated with respect to the NPV criterion in both random and flow shop environments. The results suggest that priority rules that utilize monetary information about jobs yield a higher NPV than many time-based rules in most situations, with little sacrifice in job tardiness. A well-researched time-based rule, critical ratio, also provides excellent performance when the shop is heavily loaded.
TL;DR: A graphical method is proposed as a tool for evaluating the impact of different control rules or different shop configurations upon shop performance and the invariance property of the curve is discussed.
Abstract: A graphical method is proposed as a tool for evaluating the impact of different control rules or different shop configurations upon shop performance. The shop operating characteristics curve simultaneously displays indices for the throughput rate, the flow time, and the level of work-in-process. The method of constructing and applying the shop operating characteristics curve is illustrated using several examples. The invariance property of the curve also is discussed.
TL;DR: The MPSEL system as mentioned in this paper is a system for machining parameters in a job shop, which is used for the selection of machines, tools, fluids, tool angles, and in the analysis of the compatibility between operations and work materials.
TL;DR: In this article, the synchronization of process operations of mating component parts (batches) can be an effective production planning tool that may actually decrease total throughput time where manufacturers are attempting to decrease in-process inventory.
TL;DR: It is proved that it is possible to utilize fully the bottleneck machine(s) whatever the sequencing of the jobs on the machines may be, and an algorithm is suggested to give the optimal set of sequences, i.e. the set which provides the maximal productivity with the minimal number of transportation resources.
TL;DR: In this paper, the authors present a brief overview of a shop activity manager (SAM), a shop controller which has a distributed architecture and which is based on artificial intelligence (AI) techniques.
25 Sep 1989
TL;DR: In this article, a class of augmented Petri nets is introduced as a notation for microscopic deterministic job shop models which are well suited for short-term production control, including job shop scheduling.
Abstract: Efficient short-term production control depends on the ability to forecast future behavior of a job shop when it is loaded according to a particular schedule. A simulation of the job shop process based on a well-suited job shop model can be used to evaluate that schedule according to such goals as low in-process inventory, high utilization of workers and facilities, and low tardiness so that some optimization by modifying the schedule can be performed. A dedicated class of augmented Petri nets is introduced as a notation for microscopic deterministic job shop models which are well suited for short-term production control, including job shop scheduling. It is shown how these Petri nets can be automatically transformed into CPM nets using occurrence structures. These CPM nets represent the job shop schedule. In contrast to Gantt charts they are not restricted to the information about the temporal ordering of events of the shop floor, but also contain the full causal structure of the job shop process as well as assertions about the critical path. An attempt is made to determine whether there is a fundamental limit of deterministic simulation of manufacturing facilities emerging out of chaos phenomena due to incomplete specification of deterministic models. >
Book•
01 Jan 1989
TL;DR: A comparison of production and service processes can be found in this article, where a machine-paced line flow process (Carrier Corporation-Indianapolis), a hybrid (batch/continuous flow) process (Stroh Brewery-Winston-Salem), a Worker-Paced Line Flow Process and a Service Factory (Burger King-Noblesville, IN).
Abstract: A Continuous Flow Process (International Paper-Androscoggin Mill). A Job Shop (Norcen Industries). A Batch Flow Process (Jos. A. Bank Clothiers). A Machine-Paced Line Flow Process (Carrier Corporation-Indianapolis). A Hybrid (Batch/Continuous Flow) Process (Stroh Brewery-Winston-Salem). A Worker-Paced Line Flow Process and a Service Factory (Burger King-Noblesville, IN). A Service Shop (Ogle-Tucker Buick). Mass Service (Lazarus Department Store-Castleton Square). A Professional Service (Arthur Andersen-Charlotte). A Project (Geupel DeMars-Indianapolis). A Comparison of Production and Service Processes.
Book•
01 Jan 1989
TL;DR: In this paper, the authors present a case study on FMS capacity determination and load balancing in flexible manufacturing systems, and present a decision support system for real-time production scheduling, based on the FMS loading and part type selection problems.
Abstract: A selection of contents: Strategic Issues for FMS Adoption. Two-Tiered Measurement Systems in Modernizing Plants (J.E. Ettlie). Capacity modelling of a FAS: The two-product case (I.J. Winters, M.C. Burstein). Evaluating the design of FMS (U. Nandkeolyar, D.P. Christy). Adoption of FMS in China: necessity and constraints (Z-X. Luo). A systematic assessment of the value of flexibility for an FMS (C. Chen-Hua, C. In-Jazz). Economic Issues. Multiproduct industries: A case for flexible automation (D. Gupta, J.A. Buzacott). An MIP formulation for the phased implementation of FMS modules (N.C. Suresh, J. Sarkis). Investment evaluation methodology (P.L. Pollard, R.L. Tapscott). Cost estimating for the factory of the future (P.C. Hough). System Design and Evaluation. Planning problems of FAM cells in a job shop: a case study (C.W. Dirne). Cost efficiency: an index of operational performance of FAP environments (N. Alberti, S. Noto La Diega). A case study on FMS capacity determination (M.V. Tatikonda, M.K. Crosheck). Processing rate optimization for FMS's with distinct multiple job visits to work centers (P.J. Schweitzer, A. Seidmann). An algorithm for the minimum cost configuration problem in flexible manufacturing systems (H.F. Lee et al.). Loading Problems. Tool management in AM: A tutorial (A.E. Gray, K.E. Stecke). Loading problem in FMS: part movement minimization (K. Shanker, S. Rajamarthandan). Goal-oriented heuristics for the FMS loading (and part type selection) problems (A.A. Moreno, D. Fong-Yuen). Procedure to solve part mix and tool assignment problems in FMS (C. Shu-Hsing, D. Gwo-Long). Planning. Heuristics for the FMS/MRP rough-cut capacity planning problem (J.B. Mazzola). Layout problem in FMS: recent research results and further research directions (P. Kouvelis, A.S. Kiran). Scheduling. Flexible routing control and scheduling (L. Yuh-Jiun, J.J. Solberg). The need to consider job sequencing policy when determining buffer capacity for FMC flow lines (T. Park, H.J. Steudel). Scheduling and Flow Control. On solving a model for workload allocation on parallel unrelated machines with set-ups (B.L. Dietrich, L.F. Escudero). Optimal job-order release in a robotic assembly cell (A.K. Chakravarty, J.J. Liu). Decision Support Tools for Planning and Scheduling. A decision support system for real time production scheduling (A. LeGall, F. Roubellat). The leitstand - a new tool in CAM scheduling (H.H. Adelsberger, J.J. Kanet). Software and Controls. CIMGEN: a case tool for CIM development (E.G. Mettala et al.). On-line concurrent simulation in production scheduling (W.J. Davis, A.T. Jones). Material Handling. An investigation of machine and AGV scheduling rules in an FMS (I. Sabuncouglu, D.L. Hommertzheim). Flexible Assembly Systems. Hybrid algorithms for design optimization of asynchronous FAS with statistical process control and repair (A.A. Bulgak, J.L. Sanders). Design of an unmanned flexible assembly cell (K. Krishnamurthy et al.).
01 Jan 1989
TL;DR: The paper presents the general approach adopted to design a decision support system for the problem of scheduling the operations in the shop of a large manufacturing plant.
Abstract: The paper presents the general approach adopted to design a decision support system for the problem of scheduling the operations in the shop of a large manufacturing plant.
Book•
01 Jan 1989
TL;DR: A planning system may be designed by combining a set of operation or building blocks that represent the fundamental building blocks of production planning: user communication, data base management and basic operations.
Abstract: Activities in a job shop type mechanical company can be split in production, product cycle and production cycle. The corresponding flow in each of these are materials, manufacturing specifications and product requirements. Production planning will plan and control these flows. Basic data structures are a product model and a corresponding hierarchy linked to production resources. A planning system may be designed by combining a set of operation or building blocks. These are three types: user communication, data base management and basic operations. The basic operations cover all processing necessary in production planning and represent the fundamental building blocks. A list of basic operations is suggested.
22 May 1989
TL;DR: In this article, the authors present a shop-level scheduling strategy for semiconductor wafer fabrication facility, which reduces WIP (work in process) and improves on-time ship performance.
Abstract: The authors present a strategy for shop-level scheduling in a semiconductor wafer fabrication facility, which reduces WIP (work in process) and improves on-time ship performance. Algorithms for lot-release and lot-dispatch are defined on the basis of dynamic programming techniques. The strategy is called flow rate control because it treats the production rates according to certain rules. The most important rule is the two-boundary rule that consists of a simple inventory control policy and a simple surplus control policy. Development of the strategy was motivated by three features of the wafer manufacturing process: job re-entry, the large number of machines and products, and random events such as machine failures and yield fluctuations. Two-boundary control works by first forming a virtual job shop corresponding to the manufacturing process flow. Inventory and surplus levels are calculated for each job step and compared with predetermined values. These predetermined values are calculated from the failure rates and yield fluctuations of wafer fabrication. The loading rate at each job step in the wafer fabrication process is determined by the result of the comparison. An event-driven simulator designed for job shop production simulation was used to compare the flow rate control strategy with other scheduling strategies. The results showed marked improvement in WIP levels and ship performance over these other approaches. >