Showing papers on "Job shop published in 1974"

A Loading and Balancing Methodology for Job Shop Control

Abstract: An algorithmic procedure is devised for loading and releasing work to a job shop environment. The objective of the procedure is the control and balance of workloads in the shop. The importance of s...

Labor Flexibility in Multiechelon Dual-Constraint Job Shops

Abstract: In this paper a simulation study of the effects of labor flexibility on the performance of a multiechelon dual-constraint job shop is described. Machines and workers are constraining resources in the hypothetical shop. The organizational structure of the shop consists of divisions comprised of work centers that contain machines and workers. There are fewer workers than machines. Independent variables are interdivisional and intradivisional labor flexibility. Mean flow-time, flow-time variance and worker transfers between divisions and work centers are used as measures of shop performance. Labor flexibility is shown to have a major effect on shop performance. The effectiveness of interdivisional labor flexibility as a management variable is found to be concentrated in the region of high flexibility while intradivisional labor flexibility is most effective in the region of low flexibility.

Job Shop Scheduling with Due Dates and Overtime Capability

Abstract: A scheduling procedure is proposed for the static job shop problem with job due dates and overtime capability. An example is used to demonstrate the procedure and the generation of trade-off curves relating overtime and total tardiness for use in managerial evaluation of alternative schedules. Results are reported for a set of trial problems having 30 to 98 processing operations. An extension of the procedure is described for dynamic job shop scheduling.

The Sensitivity of the Relative Effectiveness of Job Shop Dispatching Rules with Respect to Various Arrival Distributions

Abstract: The study investigates the effects which various arrival rate distributions may have on the relative success of implementing various job shop heuristic dispatching rules. Sixteen different arrival rate distributions are tested on ten dispatching rules. General conclusions imply that the distribution with respect to shape and range of the arrival rate for incoming jobs is not a significant variable in evaluating the relative effectiveness of dispatching rules.

Mathematical aspects of the 3 × n job‐shop sequencing problem

Abstract: The paper discusses mathematical properties of the well-known Bellman-Johnson 3 × n sequencing problem. Optimal rules for some special cases are developed. For the case min Bi ≥ maxAj we find an optimal sequence of the 2 × n problem for machines B and C and move one item to the front of the sequence to minimize (7); when min Bi ≥ max Cj we solve a 2 × n problem for machines A and B and move one item to the end of the optimal sequence so as to minimize (9). There is also given a sufficient optimality condition for a solution obtained by Johnson's approximate method. This explains why this method so often produces an optimal solution.

Organizational structure of dual-constraint job shops

Abstract: This paper describes the results of a simulation study to examine the effects of different organizational structures on the performance of a dual-constraint job shop production system. A hypothetical shop in which machines and workers are constraining resources is the setting of the study. The shop consists of divisions comprised of work centers which, in turn, contain machines to which workers are assigned. There are fewer workers than machines. Variations in organizational structure are achieved by different allocations of a fixed number of work centers to the divisions. Each structure is studied for three levels of labor flexibility. Mean flow-time, flow-time variance, and worker transfers between divisions and work centers are used as performance measures.

A Hierarchical Approach for a Naval Tender Job Shop Design.

Abstract: : A hierarchical approach for the determination of the manpower and machinery configuration for a naval tender machine shop is presented. The application of numerically controlled machine technology is stressed. A mixed integer programming model is developed to support aggregate decisions regarding machinery and manpower allocations. The job shop performance under the suggested aggregate characteristics is tested by a detailed simulation model. An iterative procedure links both models to ensure satisfactory overall performance. A typical naval tender machine shop workload is used in the model implementation. (Author)

Simulation of advanced manufacturing systems

Abstract: Flexible manufacturing systems (FMSes) use a variety of direct numerical control machines embedded within unique material handling systems. An FMS is a hybrid between fixed production and job shop facilities. Possible order-of-magnitude decreases are foreseen in unit manufacturing costs through the use of an FMS.The input-output conversion process of an FMS is so complex that evaluation is most readily accomplished by simulation within experimental designs. A Simscript model is in use to: determine FMS physical configuration; create decision rule sets for online computer controls; and reduce the management uncertainty in considering investment in FMS installations.

Study of the Integrated Manufacturing System for Job Shop (1st Report)

Abstract: This paper deals with problems on the process planning, especially the determination of optimum machine tools, which is considered as the bottle neck in optimization of manufacturing process in the integrated manufacturing system for job shop. An idea of optimum manufacturing pattern (OMP) is newly introduced basing on the concept of multi-levels optimization technique in a large system. An algorithm and the computer program, which is named CAPP, are developed to automatically determine the optimum kinds and numbers of machine tools. Some case studies are carried out for actual machine shops which take place in the form of a large number of small batches. The calculated results by the newly developed system (CAPP) show that about 12 % reduction in manufacturing cost may be obtained, therefore the effectiveness and feasibility of the idea OMP is proved.

A Model for Predicting the Performance of a Job Shop

Abstract: This paper is concerned with presenting a method of modelling a job shop based on queueing theory. The model is very flexible and may be used to explore the relationships between the resources available in the shop (numbers and characteristics of machines, manpower levels and skills), the workload in the shop, the mode of operation of the shop (labour allocation and priority schemes) and the resulting level of congestion within the shop.

The use of numerically controlled machine tools aboard a naval tender: a job shop design.

Abstract: A hierarchical approach for the determination of a manpower and machinery configuration for a naval tender machine shop is presented. The application of numerically controlled machine technology is stressed. A mixed integer programming model is developed to support aggregate decisions regarding machinery and manpower allocations. The job shop performance under the suggested aggregate characteristics is tested by a detailed simulation model. An iterative procedure links both models to ensure satisfactory overall performance. Typical naval tender machine shop workload is used in the model implementation. Thesis Supervisor: Arnoldo C. Hax Title: Associate Professor of Management Science ACKNOWLEDGEMENTS The author is indebted to several people for the many hours they devoted to this project. I am grateful to Dr. John H. Huth , Chief Scientist for Research and Development in the Naval Ship Systems Command, who provided the initial impetus for this study, for his support and guidance. I appreciate the efforts of MR1 Jim Tucker in the Repair Department, USS PUGET SOUND (AD-38), who provided a perspective of naval tender machine shop operations. Mr. Dave McMichael and the staff of Project TRANSIM were most helpful in setting up and running the detailed