摘要:

The integration of product design and operations could potentially enhance the ability of manufacturers to provide large variety in the product line while keeping their operations competitive. At the plant level, an improved assembly sequence can lead to superior operational response to customer demands. While this has been intuitively accepted, there is a scarcity of models that can adequately reflect the operational benefits of a costlier yet better design. In this paper, we present integrated models applicable at a plant level that can provide quantification of certain operational benefits. Further, through a computational study, we also provide qualitative insights on several issues such as the effect of: (i) features in the product line; (ii) variance of demand for the different features on the optimal assembly design; (Hi) set-up times; and (iv) life cycle of the product line.

ISSN:0740-817X    

DOI:10.1080/07408179908969903

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

We study the integrated design of strategic supply chain networks and the determination of tactical production-distribution allocations in the case of customer demands with seasonal variations. Given a set of potential suppliers, potential manufacturing facilities and distribution centers with multiple possible configurations, and customers with seasonal demands, the goal is to determine the configuration of the production-distribution system with the lowest sum of supply, production, transportation, inventory, and facility costs such that seasonal customer demands are met. We develop a mixed integer programming formulation and an integrated design methodology based on primal (Benders) decomposition. For a case study in the packaging industry, specialized acceleration techniques reduced the running times by a factor of 480. The company projects savings of 2% or $8.3 million by using the integrated rather than the optimal hierarchical configuration.

ISSN:0740-817X    

DOI:10.1080/07408179908969904

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper explores ways of conceptualizing and studying the power of coordination and strategic alliances within a manufacturing and distribution supply chain consisting of one manufacturer and one distributor. The supply chain operates to meet price-sensitive random demand of a product with a short product life cycle. We derive closed-form multi-attribute measures of performance for the supply chain in the presence of and in the absence of coordination of pricing and production/ordering decisions. The optimal coordinated pricing and production/ordering policies, as well as each party's optimal policies in the absence of coordination, are developed. Our results yield insights into basic managerial issues for this type of manufacturing and distribution supply chains.

ISSN:0740-817X    

DOI:10.1080/07408179908969905

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Faster product development and increased competition in retail industries is resulting in shorter and shorter product life-cycles. This phenomenon is making it more difficult for a firm to accurately estimate random demand of such products and to plan their one-time order quantity accordingly. In this paper, we develop a model to assess the multiple effects of coordinated - i.e., joint - stocking and prior-sale discount decisions: (i) on the reduction of demand uncertainty; (ii) on maximization of the expected profit; and (iii) on the probability of achieving or exceeding it. We develop the joint optimal decisions that maximize the expected profit and discuss a procedure for computing the probability that the realized value of the (random) profit will exceed its maximum expected value. We present qualitative results on the varying effects of joint decisions on increasing the expected profit and the probability of achieving or exceeding it. We also describe a detailed numerical study examining the effects of varying parameter values on the percentage increase in expected profit with joint decision making. The paper concludes with extensions of the model that can deal with more general situations.

ISSN:0740-817X    

DOI:10.1080/07408179908969906

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper reviews recent work on integrated analysis of production-distribution systems, and identifies important areas where further research is needed. By integrated analysis we understand analysis performed on models that integrate decisions of different production and distribution functions for a simultaneous optimization. We review work that explicitly considers the transportation system in the analysis, since we are interested in the following questions: (i) how have logistics aspects been included in the integrated analysis? and (ii) what competitive advantages, if any, have been obtained from the integration of the distribution function to other production functions within a company and among different companies? In our review we also mention whether the work has been done at the strategic level, i.e., if it concerns the design of the distribution system, or at the tactical level, i.e., if it concerns optimization problems for which the characteristics of the distribution system are provided.

ISSN:0740-817X    

DOI:10.1080/07408179908969907

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Raw material ordering policy and the manufacturing batch size for fixed-interval deliveries of finished goods to multiple customers play a significant role in economically managing the supply chain logistics. This paper develops an ordering policy for raw materials and determines an economic batch size for a product at a manufacturing center which supplies finished products to multiple customers, with a fixed-quantity at a fixed time-interval to each of the customers. In this model, an optimal multi-ordering policy for procurement of raw materials for a single manufacturing system is developed to minimize the total cost incurred due to raw materials and finished goods inventories. The carried over inventory of finished goods from the previous cycle is used as initial finished goods inventory, resulting in shifting the production schedule ahead for the next cycle. A closed-form solution to the problem is obtained for the minimal total cost. The algorithm is demonstrated for multiple customer systems.

ISSN:0740-817X    

DOI:10.1080/07408179908969908

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper focuses on the formulation and solution of the problem of planning vehicle routes for material delivery within the premises of a plant working under a just-in-time production system. The unique characteristic of this problem is that the quantity to be delivered at each of the demand nodes is a function of the route taken by the vehicle assigned to serve that node. The problem is modeled by adding a non-linear capacity constraint to the standard vehicle routing model, such that vehicle idle times and inventories at the customer locations are minimized. A heuristic solution procedure is outlined, and the formulation of a lower-bound relaxation is suggested. The performance of the heuristic solution procedure is evaluated in comparison to the lower-bound relaxation, and the heuristic procedure is shown to provide generally good results.

ISSN:0740-817X    

DOI:10.1080/07408179908969909

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The objective of this research is to develop and evaluate effective, computationally efficient procedures for scheduling jobs in a large-scale manufacturing system involving, for example, over 1000 jobs and over 100 machines. The main performance measure is maximum lateness; and a useful lower bound on maximum lateness is derived from a relaxed scheduling problem in which preemption of jobs is based on the latest finish time of each job at each machine. To construct a production schedule that minimizes maximum lateness, an iterative simulation-based scheduling algorithm operates as follows: (a) job queuing times observed at each machine in the previous simulation iteration are used to compute a refined estimate of the effective due date (slack) for each job at each machine; and (b) in the current simulation iteration, jobs are dispatched at each machine in order of increasing slack. Iterations of the scheduling algorithm terminate when the lower bound on maximum lateness is achieved or the iteration limit is reached. This scheduling algorithm is implemented in Virtual Factory, a Windows-based software package. The performance of Virtual Factory is demonstrated in a suite of randomly generated test problems as well as in a large furniture manufacturing facility. To further reduce maximum lateness, a second scheduling algorithm also incorporates a tabu search procedure that identifies process plans with alternative operations and routings for jobs. This enhancement yields improved schedules that minimize manufacturing costs while satisfying job due dates. An extensive experimental performance evaluation indicates that in a broad range of industrial settings, the second scheduling algorithm can rapidly identify optimal or nearly optimal schedules.

ISSN:0740-817X    

DOI:10.1080/07408179908969910

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper is motivated by the problem of assigning semiconductor fabrication wafer lots to customer orders of various sizes. The goal of this research is to develop a method for deciding, on a given day, which orders to fill and the assignment of available lots to orders. This decision should be made in order to effectively utilize the capacity of the assembly/test facility, to minimize excess product that must be sent to a storage facility, and to maximize on-time delivery of customer orders. This problem can be formulated as an integer program with a nonlinear objective and nonlinear constraints. Because of the complexity of this formulation we decompose the problem into two integer linear programs and solve them in sequence by heuristic methods. The performance of the heuristic is analyzed using a representative data set. Based on this analysis, it is shown that our greedy heuristic performs significantly better than current practice.

ISSN:0740-817X    

DOI:10.1080/07408179908969911

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0740-817X    

DOI:10.1080/07408179908969902

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor