摘要:

A mixed integer 0–1 programming formulation of a Project Scheduling-Materials Ordering Problem (PSMOP) is presented that provides an optimal schedule of project activities and materials orders. It is proven that an optimal solution may be found by decomposing the problem into the derivation of the project schedule and the subsequent derivation of materials lot sizes.

ISSN:0740-817X    

DOI:10.1080/07408178708975378

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A general model for a class of production lines with two unreliable stations, a finite capacity interstation buffer, discrete items, constant cycle time, and synchronous transfer is presented. The model is applicable to a broad range of production lines with various item service mechanisms, item transfer mechanisms, station breakdown mechanisms, and station repair mechanisms. The model provides insights into the general properties of production lines and gives rise to a general recursive solution for the steady-state probabilities. Sufficient conditions are given for the two special cases, the matrix geometric case and the scalar geometric case, which permit the efficient computation of the production rate.

ISSN:0740-817X    

DOI:10.1080/07408178708975379

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In this paper we present a model for multi-echelon repairable systems with batch ordering policy at the bases. Such an ordering policy is desirable when demand rates and/or the set up cost for ordering are relatively high. Operating characteristics of such a system are analyzed. A two-parameter approximation scheme for the distribution of the number of orders outstanding and consequently backorders is developed, and its performance evaluated. It is found that, under a variety of scenarios including both finite and infinite servers at the repair facility, the approximation scheme is very effective in providing a relatively simple means to determine the stocking levels at both the depot and the bases to minimize the cost of inventory holding and backorders. For the special case when the batch size is one, we confirm the effectiveness of the use of the negative binomial distribution as an approximation for the distribution of orders outstanding, as suggested by recent studies, under a much more general setting.

ISSN:0740-817X    

DOI:10.1080/07408178708975380

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper presents a decomposition method to evaluate the performance measures of a capacitated transfer line with unreliable machines and random processing times. The decomposition is based on approximating thek- 1-buffer system byk- 1 single-buffer systems. Numerical examples indicate that the approach is accurate as long as the probability that a machine is starved and blocked at the same time is small.

ISSN:0740-817X    

DOI:10.1080/07408178708975381

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Several methods have been proposed and tested for calculating lower bounds on the objective function of facilities location problems. These methods contribute to the efficiency of iterative solution methods by allowing the user to terminate the computation process when the objective function comes within a pre-determined fraction of the optimal solution. Recently, the dual of the facilities location problem has been proposed as an alternative method for computing lower bounds. In this paper, the dual is compared with three other lower bounds.

ISSN:0740-817X    

DOI:10.1080/07408178708975382

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A real-time interactive model of a flexible manufacturing system (FMS) is described, with emphasis given to the system's structure and to the model's interactive component. An attempt is made to illustrate how the model can be used to extract knowledge concerning human strategies at supervisory control of an FMS, knowledge that would otherwise be largely inaccessible. This knowledge is considered essential for the development of expert systems that would serve as supervisory controllers of FMSs.

ISSN:0740-817X    

DOI:10.1080/07408178708975383

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The purpose of this paper is to demonstrate a method for determining the expected discounted future costs incurred from a lifetime warranty. Distributions of phase type are used to model the useful life of the good under warranty. The costs realized from the warranty are assumed to be both fixed and variable in nature. Under relatively general stochastic assumptions, a computationally tractable expression for the total expected discounted future cost is derived.

ISSN:0740-817X    

DOI:10.1080/07408178708975384

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The concept of using labeled feature marks and a position transformation algorithm is proposed for computer vision systems with a single camera to facilitate part positioning, orientation, and vertical depth sensing. A calculation procedure is reviewed and experimental examples of the use of the general concept are presented. The influence of different factors on the errors in this proposed positioning method are also discussed. Finally, further research opportunities are presented.

ISSN:0740-817X    

DOI:10.1080/07408178708975385

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A splitting algorithm based on Shannon measure of mutual information is presented. The algorithm is designed to select individual levels of qualitative variables that are significantly related to a skewed dichotomous dependent variable. The use of this technique in conjunction with a grouping algorithm based on similar principles is illustrated with an actual application.

ISSN:0740-817X    

DOI:10.1080/07408178708975386

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In a Just-in-Time (JIT) production system with Kanbans, as used by the Japanese, the number of Kanbans employed at each workcenter remains relatively constant from month to month even though demand may change, This occurs because of the unique (and stable) conditions inherent in the production environment of Japanese firms. However, a number of American firms have considered or attempted the implementation of a JIT system without a similar production environment, thus, necessitating that the number of Kanbans at each workcenter be adjusted periodically. In this paper, a procedure for dynamically adjusting the number of Kanbans at workcenters in an unstable production environment is presented and analyzed. The adjustment methodology is presented in a step-by-step manner. This is followed by three examples presented within the context of a simulation model of a hypothetical shop. The first example will illustrate the methodology while the last two examples will demonstrate how well the methodology reacts to the dynamics of the shop operation.

ISSN:0740-817X    

DOI:10.1080/07408178708975387

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor