摘要:

In Part I in a previous issue, the authors developed a procedure for incorporating dynamic productivity considerations into aggregate planning models. However, the dynamic cost functions of these models result in heterogeneous decision systems which are difficult to solve. In this article a solution methodology is discussed that was developed for dynamic aggregate planning models. In addition, the results from using a dynamic productivity aggregate planning model are analyzed. It is concluded that dynamic productivity can be significant; incorporating these considerations into a model can provide more realistic results.

ISSN:0740-817X    

DOI:10.1080/05695558308974649

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A flow-shop-type production line where the stations are subject to breakdown is modeled as a series of queues. The objective is to find the allocation of interstage buffer capacities that maximizes total profit. The stations, which are modeled as single-server queueing systems, have completion-time distributions of two-stage Coxian type. After a standard transformation to a phase-type state representation, the new system gives rise to a Markov chain. The balance equations for this chain are solved by successive approximations to find the steady-state probability distribution of the number of items at each station, once the buffer capacities are given. A search procedure has been employed to find the optimal buffer capacities.

ISSN:0740-817X    

DOI:10.1080/05695558308974650

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

This paper presents a unified approach for the solution of the minimax and maximin location problems subject to constraints in the plane and on the sphere. The constraints limit the solution to be inside some circles and/or outside some other circles. Four distance measures are considered: Euclidean in the plane, shortest arc distance on the sphere, and general monotonic functions of each. Computational results are presented.

ISSN:0740-817X    

DOI:10.1080/05695558308974651

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

This paper addresses the development of a matrix model for the initial loading procedure in material requirement planning systems with variable lead time. This model expresses the relationship between the planned production quantity in the Master Production Schedule and the production lead time required. Using this model, an analysis of the functions of buffering techniques before loading are discussed. Methods for allocating safety stock and safety lead time using the service level approach are presented to accommodate quantity or lead-time uncertainties. The matrix model is used to study fixed-lead-time loading. The relationships between fixed-lead-time loading and variable-lead-time loading are examined. Methods for allocating buffering quantities for fixed-lead-time loading are developed.

ISSN:0740-817X    

DOI:10.1080/05695558308974652

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The effective utilization of limited resources within a large police department represents a major organizational goal. This paper describes a project executed and implemented within the Indianapolis Police Department to plan communications support effectively. By properly identifying the appropriate staff levels and scheduling personnel when needed, the communications department's performance improved.

ISSN:0740-817X    

DOI:10.1080/05695558308974653

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

In most reported studies of job dispatching rules the primary criterion for evaluating alternative rules has been the mean number of jobs in the shop, or the equivalent. This paper argues that the meanvalueof jobs in the shop is a more generally useful measure because it is a determinant of work-in-process (WIP) inventory carrying cost. For certain simple single-server systems the shortest processing time rule (SPT) is known to be optimal on the first criterion. A value-weighted version of SPT, termed SWPT, is optimal on the second criterion (mean value). We show by means of a simulation study that introduction of a similar dollar-weighting feature into more complex rules is effective in reducing mean WIP inventory, even in complex multimachine stochastic systems. Since our suggested dispatch rule modifications require value weighting, correct valuation of jobs is essential. The subject of how to determine the value of a job dynamically as it moves through the shop is discussed.

ISSN:0740-817X    

DOI:10.1080/05695558308974654

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The net present value criterion of discounted cash-flow analysis is the appropriate method for ranking the options in many capacity expansion decisions. This paper presents and discusses a 0-1 programming model that facilitates this type of analysis. Two actual implementations for Owens-Corning Fiberglas are discussed.

ISSN:0740-817X    

DOI:10.1080/05695558308974655

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Parts-orienting devices have long been recognized as critical elements of mass production systems. In batch manufacturing, workpiece orientation has typically been accomplished manually because a part's production volume usually does not economically justify the design and construction of a dedicated parts feeder. Different approaches to workpiece orientation have been undertaken by various researchers. This paper discusses some of those approaches and offers an alternative approach consisting of a methodology for developing programmable feeders based on conventional parts-feeding technology.

ISSN:0740-817X    

DOI:10.1080/05695558308974656

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

In this paper the problem of scheduling jobs on a single machine to minimize the weighted number of tardy jobs is examined. It contains the framework for a new branch-and-bound procedure as well as the first extensive computational study of the problem. Results indicate that large problems, e.g. 50 jobs, can be solved in just a few seconds of computer time. Further, the computational results provide insight into how various problem parameters affect the solution difficulty of particular problems.

ISSN:0740-817X    

DOI:10.1080/05695558308974657

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A model of a two-echelon (two levels of repair, one level of supply) repairable-item provisioning system is presented. It is desired to find the capacities of the base and depot repair facilities as well as the spares level which together guarantee a specified system service level at minimum cost. Closed queueing network theory is used to model the stochastic process, and an implicit enumeration algorithm is used to solve the optimization problem.

ISSN:0740-817X    

DOI:10.1080/05695558308974658

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor