برنامه ريزي و زمان بندي سفارشات در واحد نورد سرد مجتمع فولاد مباركه

چكيده انگليسي :

Planning and Scheduling of Orders in Cold Rolling Unit at Folad Mobarakeh Complex Sohrab Hashemi Nezhad s hasheminezhad@in iut ac ir Date of Submission 2011 03 15 Department of Industrial Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Mehdi Bijari bijari@cc iut ac ir Abstract Nowadays the growing complication in the productive industries and need for more efficiency utilization of production cycle modern technology more flexibility better quality of productions better satisfying of the customer s expectations and lower costs have been changed the production appearance In the steel industry that involves with large amount of wealth labor and energy flow a small improvement in planning has significant consequences such as reducing costs energy consumption production time delivery time and also increasing customer satisfaction This research aim to present a efficient model in order to schedule the orders in the product line of cold rolled in the Esfahan s Mobarakeh Steel Company so that beside the decreasing the inventory level and optimum usage of production line the costs of delays will be decreased that cause to uplifting of the reputation of the company In this study in addition to providing production planning methodologies in different areas of the industry three models of planning and scheduling orders in cold rolling area with regard to possible output of hot rolling is presented The first model is a multi objective planning model which minimizes the costs of delays inventory keeping and line shutting down The second model is a linear programming model which has two general cases This model can be applied in industries like aluminum copper textile carpet weaving dyeing and generally in each industry that has a multi stage multi product production flow According to certain features of steel industry such as high number of orders weakness of software in dealing with these orders and other technological constraints the third model is presented which is a Mixed Integer Linear Programming In the case that the number of variables is very high and the computer cannot respond in an acceptable time a heuristic algorithm to improve the initial solution from the third model without limitation zero and one is presented The third model is solved by applying real data of Mobarakeh Steel cold rolling in two stages At first the third model without considering zero one constraint is solved In what follows the zero one and some other constraints obtained from heuristic algorithm are added to the model and the model is solved by GAMS 23 5 2 win32 software All the computations are implemented on computer with 32GB RAM and CPU 2 93GHz The optimal solution i e the required amount of production of each product on each machine per day in three months time horizon is obtained The output plan demonstrates a remarkable reduction in the volume of delayed orders and also in unused capacity in machineries Actual amount production of cold rolled machines which collected from 2011 01 21 to 2011 03 10 has been selected in order to compare with the outputs of third model with additional limitations which collected from cold rolled planning unit The results show that by running and implementing this model the 17 2 increase in number of delivered orders and 16 9 increase in amount of delivered orders that will be occur in compare with status quo In addition we will have 10 3 increase in usage of the machines capacity Keywords production planning scheduling orders multiple objective planning cold rolling

هاشمي نژاد، سهراب

برنامه ريزي و زمان بندي سفارشات در واحد نورد سرد مجتمع فولاد مباركه

برنامه ريزي توليد , برنامه ريزي چند هدفه