Journal of Japan Industrial Management Association
Online ISSN : 2187-9079
Print ISSN : 1342-2618
ISSN-L : 1342-2618
Volume 50 , Issue 5
Showing 1-12 articles out of 12 articles from the selected issue
  • Type: Cover
    1999 Volume 50 Issue 5 Pages Cover9-
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
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  • Type: Cover
    1999 Volume 50 Issue 5 Pages Cover10-
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    Download PDF (49K)
  • Type: Index
    1999 Volume 50 Issue 5 Pages Toc5-
    Published: December 15, 1999
    Released: November 01, 2017
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  • Hiroshi OHTA, Aritoshi KIMURA
    Type: Article
    1999 Volume 50 Issue 5 Pages 275-282
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    The design of X^^- charts and X^^--R charts for economic process control has received considerable attention. Recently, the economic design of a dynamic X^^-Chart in which the design parameters, that is the sample size, the control limit coefficients and the sampling interval are dynamic and varying over time has also been studied. In this study, considering the simultaneous control of process average and variability, we discuss the economic design of dynamic X^^--R charts. Concretely, we propose a process control model and cost model under the Weibull distributed-shock model, and determine the initial values and dynamic rules for varying the values of the sample size, control limit coefficients and sampling interval which minimize the average loss cost per hour for the proposed cost model.
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  • Xi SUN, Akira NISHIURA, Kazuko MORIZAWA, Hiroyuki NAGASAWA
    Type: Article
    1999 Volume 50 Issue 5 Pages 283-289
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    In this paper effective heuristics are proposed for minimizing makespan in machine-fixed, machining-assembly flowshop scheduling, where parts of each job are machined on prespecified parallel machines in the machining stage and then assembled in the assembly stage after all component parts are been completed. Since this problem in NP-complete, several heuristics have been proposed so far by converting the original problem into the usual two-machine flowshop problem which can be solved through Johnson's algorithm. However, the tight upper boundaries for the relative error in these heuristics are very large, i.e., 50〜100%. The heuristics proposed in this paper exploit the basic idea of Johnson's rule, Gupta's idea and the results of worst/difficult case analyses without any conversion of the original problem into the usual two-machine flowshop problem. Numerical experiments showed that the proposed heuristics can efficiently solve all problems generated randomly for the two parallel-machine case, and can solve more than 99.0 percent of the problems for three and five parallel-machine cases. These heuristics are superior to the usual branch and boundary algorithm with a limited computation time of 30 minutes, not only in efficiency but also in accuracy.
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  • Katsumi MORIKAWA, Nobuto NAKAMURA
    Type: Article
    1999 Volume 50 Issue 5 Pages 290-298
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    This paper proposes a distributed scheduling approach to the job shop scheduling problem. Our basic idea is that by distributing the scheduling procedure among multiple computers, the computing time can be reduced even we use some simple scheduling algorithm. To minimize the maximum completion time, the straightforward enumerative algorithm is used to generate all active schedules and the one-machine sequencing algorithm is adopted to obtain the lower boundary of the maximum completion time. The above procedure is implemented in multiple clients independently and one server coordinates the entire procedure. Each client receives the problem from the server, reserves the specified number of sub-problems, and then solves the remaining problem. One of the reserved sub-problems is transferred to the server as a new problem for the clients. The server also receives the current best solutions from the clients and the best value is sent to all clients immediately. Interruption of processing to generate a new problem is also activated if one or more clients enter the standby state. From numerical experiments using one server and up to nine clients, we have found that by increasing the number of clients, the computing time could be reduced greatly in some problems. In addition, three or more clients were required to solve some five-machine, twenty-job problems. However, in some cases, the computing time could not be reduced or the degree of reduction was not enough when the number of the computers was increased. The remaining research issues on distributed scheduling are also clarified.
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  • Masaaki IMABAYASHI
    Type: Article
    1999 Volume 50 Issue 5 Pages 299-307
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    The traditional method of variance analysis of variable overhead costs under standard costing simply analyzes total variance into efficiency variance and budget variance. But this method implicitly assumes a linear function in production department and service department activities. Therefore, budget variance may include efficiency variances of service departments. The purpose of this paper is to propose a new variance analysis model. The model includes a simultaneous equation method in order to allocate service department costs. It also considers multiple-activities that are quantities of output, activities levels of production department, activities of service departments services, activities of service departments, and quantities and prices of service departments cost elements. There are two methods to propose this allocation method, causal relationship, and sensitivity analysis. The former notices all routes from service departments and production departments to products. It leads to a suitable solution, but needs many calculations. This paper proposes a simpler method. The new method, firstly, sets up an allocation model using a simultaneous equation. Secondly, we calculate the service departmental charge with variables, which are represented by "standard variables" (model 1) . Thirdly, we change one "standard variable" to an "accrual variable" (model 2). Lastly, we define the overhead cost variables by the differences between the cost of a product calculated by models 1 and 2. The proposed method investigates the usefulness of this model by representing the mathematical formulations and providing the possibility of furnish useful information for cost control.
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  • Jun IMAIZUMI, Susumu MORITO
    Type: Article
    1999 Volume 50 Issue 5 Pages 308-315
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    We consider a two-stage hybrid flow shop scheduling problem minimizing makespan. The problem has some features, namely, i) a job in the upper stage can be split up into sub-jobs in the lower stage, and ii) time overlap production is permitted, which theoretical scheduling models have never contained. We regard it as a combinatorial optimization problem and propose methods of obtaining the lower boundary of makespan and an algorithm based on a branch and boundary method. We also discuss efficiency of the algorithm by computational experiments. The motivation for this research is a real scheduling problem in the processing industry.
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  • Masao YOKOYAMA
    Type: Article
    1999 Volume 50 Issue 5 Pages 316-325
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    A new optimization model for the commodity distribution system consisting of distribution centers and consumer points and its calculation procedure are discussed. In this paper, demand is assumed to be a random variable whose probability distribution is known and stationary, and an integrated model is built where both inventory control and transportation problems are considered simultaneously. The assignment of consumer points to distribution centers in not fixed. The problem is formulated as an optimization problem to minimize the expectations of total inventory holding costs, shortage costs and transportation costs, where the decision variables are the target inventory and transportation amount. The techniques of simulation and linear programming are used to calculate the expected costs, and an original direct search method is developed in order to decide to optimum target inventory. A genetic algorithm is also tested and compared with the proposed direct search method. The meaning of the model in this paper, as well as the effectiveness of the proposed calculation procedure, is clarified by numerical examples and computational experiments.
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  • Yousuke SANBAYASHI, Toshio UENO, Takao OHKUBO, Mitsuyuki KAWAKAMI
    Type: Article
    1999 Volume 50 Issue 5 Pages 326-332
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    The structure of movement consists of the mixture of many elements such as sorting, quality, quantity, velocity and frequency of operation. It becomes more complicated according to structural conditions, and a kind of bewilderment is detected in the movement and information processing behavior. This bewilderment has a negative influence on work efficiency and productivity. By studying manual assembly line operations, we clarify that the bewilderment phenomenon and psychological load appear at a certain cycle time and in complicated operation processes. The objective is to determine an ideal assembly line system under the influences of bewilderment and psychological load. This study was performed using experiments of model operation. The results are as follows. The appearance of bewilderment is influenced by the arrangement of cycle time. We found an optimal cycle time from the balance loss and bewilderment in operations. A theoretical formula equation is utilized for the number of minimum operation processes with bewilderment. The difference in cycle time effects visual functions and subjective fatigue.
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  • Katsuhiko TAKAHASHI, Nobuto NAKAMURA
    Type: Article
    1999 Volume 50 Issue 5 Pages 333-340
    Published: December 15, 1999
    Released: November 01, 2017
    JOURNALS FREE ACCESS
    In order to realize agile control for multi-stage production systems, we have developed a reactive Kanban system. In the previous system, the unstable changes in product demand can be detected by monitoring the time series of demand data and detecting unstable change with the exponentially weighted moving averages chart. For the detected change, the previous system adjusts the number of Kanbans at each inventory point as a response to the change. By the dynamic adjustment of the number of Kanbans for the unstable changes in product demand, the previous system can maintain the required level for the mean waiting time of product demand by minimizing the total of the mean work-in-process inventories. However, in the previous system, the number of Kanbans is allocated equally to each inventory point. As shown in previous literature on determining the number of Kanbans, uniform allocation is not always optimal for minimizing the total of the mean work-in-process inventories. Based on that fact, this paper proposes a reactive Kanban system by allocating the number of Kanbans for each inventory point. Similar to the previous system, the proposed system can detect the unstable change of product demand and adjust the number of Kanbans as a reaction to the unstable change. However, in the proposed system, the optimal number of Kanbans for each inventory point is determined based on simulation results for minimizing the total of the mean work-in-process inventories to satisfy the required level for the mean waiting time of product demand. In addition, the proposed reactive Kanban system is modified by combining the system with the previous system where the number of Kanbans is allocated equally to each inventory point. The effectiveness of the proposed system is investigated with simulation experiments.
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  • Type: Appendix
    1999 Volume 50 Issue 5 Pages App5-
    Published: December 15, 1999
    Released: November 01, 2017
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