Predicting the production schedule of paddy-rice nursery

The objective of this study was to develop a linear programming model to an alyze the production schedule of rice seedlings grown in the nursery. The m odel can help the managers of rice seedling centers in Taiwan to make bette r production decisions and maximize profit tall monetary units are expresse d in US dollars). To verify the model, a rice seedling center was chosen fa r analysis of the first rice crop in 1997 The results show that the cost is about $51,856 yielding a profit of about $21,861 to supply 91,385 boxes of seedlings. The maximum number of boxes in the greening field is 4,600. The minimum production in each batch affects the cost significantly. The resul ts show costs of about $41,884 for 4,000 boxes batch(-1), while costs rise to about $56,522 for 6,000 boxes batch-l. Consequently, using the model to predict the production schedule not only reduces costs but also provides th e seedling in the best status for transplanting. The demand quantities of t he boxes in each day during the transplanting period can be expressed by a fourth-order polynomial. Here, a demand quantity ranging from 73,928 to 110 ,892 boxes is generated by the polynomial to analyze the production schedul e. The result shows that the production scale could be expanded to about 11 0,892 boxes with the same hardware. In this status, the profit could be inc reased to about $26,667, and the cost/profit ratio is 2.35. The relationshi p between supply quantity scale (x) and greening field size (yl can be calc ulated by a regression formula (y = 0.4609x + 3.143), where both units are in 10, 000 boxes.