Project Management
Nima Moradi; Shahram Shadrokh
Abstract
One of the classes of the project schedule is the Material Procurement Scheduling (MPS) problem, which is considered besides the material allocation to warehouse (MAW) problem recently. In the literature, the Simultaneous Solution of MPS-MAW is investigated by considering one warehouse and unlimited ...
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One of the classes of the project schedule is the Material Procurement Scheduling (MPS) problem, which is considered besides the material allocation to warehouse (MAW) problem recently. In the literature, the Simultaneous Solution of MPS-MAW is investigated by considering one warehouse and unlimited capacity of the warehouses most of the times. In this paper, we propose the propositional and mathematical model of the simultaneous MPS-MAW with multiple warehouses and the limited capacity at the whole of the horizon planning for each warehouse. The proposed model aims to obtain the best ordering point, selection of the best suppliers, the best activity start, and the fair material distribution to the warehouses as possible by the given objective function. The proposed model is NP-hard, so a metaheuristic namely simulated annealing is proposed to reach the acceptable but not optimal solutions in a short time. Also, to overcome the complexity of the model, the encoding of the decision variables have been done by adding the auxiliary variable. Comparing the solutions of the small problems with the exact methods shows the validation of the proposed SA. Also, the design of experiments shows the significance of the model and each SA parameters. Finally, by the optimum values of the SA parameters, the large problems have been solved at acceptable times.
Hamidreza Jafari; Alborz Hajikhani
Volume 3, 1(4) , December 2016, , Pages 30-38
Abstract
One of the main problems in production process of composite curly sheet process is long time duration of impregnability of needle mat to resin operation and high costs of this operation. Increased time of impregnability operation in production process caused the occurrence of ravine and consequently ...
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One of the main problems in production process of composite curly sheet process is long time duration of impregnability of needle mat to resin operation and high costs of this operation. Increased time of impregnability operation in production process caused the occurrence of ravine and consequently the output amount of production line is dramatically reduced. Removing ravine or reducing its time, has direct effect on production increase therefore the cost price of final product will decrease too. In this article first by using design of experiment technique, the effective factors on reducing operation time in production process are identified, in next stage, appropriate functions for variables of time respond and direct cost of impregnability operation was processed as separated on each agent level. Then, using multiple objective design making techniques, optimum levels of each factor for each formed model was determined and finally, the best achieved answer from processed models is chosen as optimum final answer. Model sensitiveness toward changes in importance degree of each of the aims is also analyzed and studied in comparison with each other.