Analysis of steel industries in thailand : Case study of production planning and control by determination of time limited free back orders.

Abstract

The objectives of this research were to find the distribution of food demand for laying hens and to find the optimum amount of that food production which had minimum cost. The data consisted of customer purchase orders for the food of laying hens, price of food for laying hens, cost per unit for the food inventory, cost related to food of laying hens in which the food was out of stock, such as fine, overtime, urgent purchase for material. They were collected in 2008-2009 form a factory in Nakhonratchasima province. The collected data were analized in order to explore the distribution of the monthly food demand for the laying hens and to see the rate of inventory per unit. The results were used in the stochastic linear programming model for aggregate planning in which the optimum production, minimum cost, could be obtained. Programming algorithm in MATLAB and tools in Linprog software were used to get the solution. The distribution of the food demand for laying hens and the random numbers were used in the model. The study found that the distribution of food demand for laying hens every month has normal distribution (January to December). The monthly average amount of production from January to December were 10936.94, 12913.74, 11898.12, 13096, 15443.26, 14916.33, 10322.64, 10818.21, 11393.11, 11700.72, 9706.05 and 11702.05 respectively. The minimum total cost average for 12months was Baht 62,422,386.98.