摘要:

ABSTRACTThis paper investigates the effects of partitioning job shop work centers to implement cellular manufacturing. Analytical models are utilized to show that partitioning leads to adverse effects on flow characteristics. The setup reduction introduced in partitioned systems has to overcome these adverse effects before leading to the benefits associated with cellular manufacturing. It is shown that partitioned systems with an insufficient degree of setup reduction are inferior to unpartitioned systems. Two new parameters relevant to this context, the breakeven setup reduction factor and flow ratio, are introduced for the design of viable cellular manufacturing systems. These insights are verified using a shop‐level simulation experiment, assuming non‐Markovian conditions. The experimental factors include lot size, setup reduction factor, cell size and allowance of inter‐cell movements. It is shown that the results are consistent with analytical insights in indicating the range of parameters in which cellular manufacturing may compare favorably with the best of the functional‐layout

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00389.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe kanban system is a pull method of production control in which the material‐handling operation between two stations is initiated by the downstream station. Most often, because of limited transportation resources, the physical distance separating workstations, or other factors, the material‐handling operation is performed periodically. The number of withdrawal kanbans must be set large enough to satisfy production requirements over the period between occurrences of the material‐handling operation‐the withdrawal cycle time. This paper presents a decomposition approximation for kanban‐controlled flow shops that explicitly considers the withdrawal cycle time. Several examples are given to show how the approximation method can be used to determine the required number of kanbans, the required withdrawal cycle time

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00390.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTFixed interval scheduling is studied in the context of a rolling horizon framework that is developed by building on previous work in the master scheduling area. The rolling horizon framework includes a stationary scheduling model which uses the “time fencing’concept by partitioning the planning horizon into three sections. The lengths of these sections and the frequency at which the stationary problem is updated and resolved are discussed as parameters of the rolling horizon model. Two different interpretations of the freeze interval parameter are examined, enabling confirmation and clarification of results presented in an earlier study. Details are given for three methods of calculating safety stocks as a function of rolling horizon parameters, including a method which results in optimal safety stock levels. A comparison of the safety stock methods shows that the constant safety stock method can result in inventories that are significantly above optimal under certain conditions, whereas the constant service level method consistently yields nearly optimal resu

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00391.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThis paper reports the results of simulation experiments that compared the inventory efficiency (i.e., the customer service level provided by a given level of inventory) for two different inventory policies. One of these policies uses time‐phased information on future demands like that found in material requirements planning (MRP) systems, while the other (the reorder point or ROP policy) relies on forecasts implicitly based on average past demands. After establishing that the MRP policies dominate for reasonable conditions, the uncertainty of the forecasts was manipulated until the policy preference was reversed. It requires a very perverse relationship between the forecast and actual demand before ROP beats MRP on inventory efficienc

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00392.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTPaced assembly lines are widely used in repetitive manufacturing applications. Most previous research on the design of paced lines has assumed that each task along the line can be performed by only one worker (or a fixed number of workers). In many cases, however, task duration times may be reduced by increasing the number of workers or changing the equipment assigned to work stations. Thus, the problem becomes one of assigning resource alternatives (e.g., workers and/or equipment) and tasks to work stations to minimize total cost for a desired production rate. For this problem, we present three procedures. The first formulates the problem as a shortest path problem and guarantees optimality. The second and third are heuristic adaptations of the shortest path procedure that are capable of solving large problems. The procedures are compared in terms of solution quality and computation time on a set of 128 randomly generated problems for which optimal solutions could be found. Our simulation results indicate that the choice of procedure depends on problem complexity and resource costs.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00393.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe nucleolus method has been suggested in the literature as a means for accounting decision makers to allocate joint costs in situations where entities share a common resource. The nucleolus has the advantage, vis‐à‐vis other methods, of maximizing the benefit to the least‐well‐off entity or groups of entities, and therefore reducing the possibility that one or more entities may desire to withdraw from the sharing arrangement. The nucleolus is basically a linear programming model. Because of its formulation, the nucleolus may yield multiple optimal solutions. No reformulation of the nucleolus seems to exist to overcome this problemThe minimum total propensity to disrupt (MTPD) is suggested as an extension of the nucleolus to identify unique values for allocations with multiple solutions. The MTPD, while exhibiting deficiencies as a stand‐alone method, is similar in overall objective to the nucleolus and its mathematical function possesses a unique minimum. It is therefore the logical method for identifying a unique nucleolus solution. The use of the MTPD extension is critically examined through a representative a

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00394.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTIn response to increasing costs and reductions in manpower, the Tactical Air Command (TAC) of the USAF experimented with a specialized productivity measurement model known as data envelopment analysis (DEA). A medium‐sized application of DEA was employed by TAC to evaluate the productivity of its seventeen subordinate vehicle maintenance sections over a four‐year period. The application reports gains in productivity and the reactions of the field managers to the use of

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00395.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTChance constrained programming concepts are used to formalize risk and return relations which are then modeled for use in an empirical study of mutual fund behavior during the period 1984 through 1988. The publicly announced strategies of individual funds are used to form ex ante risk classifications which are employed in examining ex post performance. Negative relations between risk and return held in every year of the period studied. The bearing of these negative risk‐return findings for the Bowman paradox, as studied in the strategic management literature, are thus extended from the industrial firms studied by Bowman (and others) and shown to be present even in these investment oriented mutual funds in each of the years of the great bull market from 1984 through 1988. Finally, our use of chance constrained programming enables us to separate risk from return behavior and evaluate their relative strengths as sources of these negative relations, which are found to be more in the returns than the risk

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00396.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe results of a field study investigating the determinants of decision support systems (DSS) success are presented. A multivariate model was developed and tested using multiple regression hierarchical analysis on responses from 118 DSS users. Several specific hypotheses are also proposed and tested. Data analyses indicate that DSS success, as measured by DSS satisfaction and perceived benefits, depends on several factors: previous user experience with DSS, user involvement, user training, top management support, information sources, the level of managerial activity, and task structure, difficulty and interdependence. Based on the research results, several suggestions are made to improve the likelihood of successful DSS implementation.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00397.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTAlthough recent research has identified attitudes towards ambiguity and risk to be important determinants of choice behavior [8] [18], no prior work jointly assessed the roles of both attitudes. We conducted a laboratory experiment using a real decision scenario and conducted exploratory analyses of the relationship between attitudes towards risk and ambiguity and the decision taken by the subjects. The results support the prediction that attitudes towards both risk and ambiguity affect choice behavior. Our exploratory analyses indicate interesting avenues for future research, including an examination of the decision process itself.

ISSN:0011-7315    

DOI:10.1111/j.1540-5915.1992.tb00398.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY