A variety of objective criteria are used in optimizing the flexible manufacturing system set-up problem in the academic literature. The literature also provides evidence that the objective criteria used in academic st...
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A variety of objective criteria are used in optimizing the flexible manufacturing system set-up problem in the academic literature. The literature also provides evidence that the objective criteria used in academic studies are often the least important in practice and that inventory related costs are rarely considered as an objective criterion. This study compares the flexible manufacturing system set-up problem across a set of strategically selected objective criteria including an inventory cost criterion. The comparison is done over varying set-up costs to inventory carrying cost ratios and machine workloads. The study provides guidelines on the merits of using each objective criterion under different conditions. The models used in the study included large mixed integerprogramming problems and quadratic programming problems with continuous and binary variables present. The binary variables in the quadratic program give the problem a combinatorial nature. In order to circumvent the combinatorial nature of the problem, we have used a combination of generate-and-test and constraint propagation strategies to generate the feasible values of the binary variables at the constraint level and to propagate the feasible binary values into the models. Generate-and-test and constraint propagation strategies used in conjunction with mathematical programming are shown to greatly simplify generating solutions to a family of problems that are otherwise considered intractable. (c) 2007 Elsevier Ltd. All rights reserved.
Equipment failures can have significant implications in terms of cost and customer satisfaction. Reducing the time required to find the cause of a failure can provide large cost savings and help preserve customer good...
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Equipment failures can have significant implications in terms of cost and customer satisfaction. Reducing the time required to find the cause of a failure can provide large cost savings and help preserve customer goodwill. Single-item discrete sequential search models can be used to sequence the tasks in diagnostic search to minimize the expected time required to find the cause of the failure. We increase the utility of the single-item discrete sequential search model by developing a formulation that includes simple precedence relationships as well as sequence dependent relationships defined by group activities. This formulation can be applied to a number of other problems including determining the sequence for multiple quality control tests on an item, scheduling oil well workovers to maximize the expected increase in oil production, and sequencing tasks in a research project where there is a technological risk associated with each task.
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