We have developed an order level inventory system for deteriorating items with demand rate as a ramp type function of time. The finite production rate is proportional to the demand rate and the deterioration rate is independent of time. The unit production cost is inversely proportional to the demand rate. | Yugoslav Journal of Operations Research 26 (2016), Number 3, 305–316 DOI: AN ECONOMIC ORDER QUANTITY MODEL WITH RAMP TYPE DEMAND RATE, CONSTANT DETERIORATION RATE AND UNIT PRODUCTION COST Prasenjit MANNA Department of Mathematics, Jadavpur University, Calcutta 700 032, India jit@ Swapan Kumar MANNA∗ Department of Mathematics, Narasinha Dutt College, Howrah-711104, ., India skmanna− 5@ Bibhas Chandra GIRI Department of Mathematics, Jadavpur University, Calcutta 700 032, India bc1iri@math. Received: May 2014 / Accepted: June 2015 Abstract: We have developed an order level inventory system for deteriorating items with demand rate as a ramp type function of time. The finite production rate is proportional to the demand rate and the deterioration rate is independent of time. The unit production cost is inversely proportional to the demand rate. The model with no shortages case is discussed considering that: (a) the demand rate is stabilized after the production stopping time and (b) the demand is stabilized before the production stopping time. Optimal costs are determined for two different cases. Keywords: Ramp Type Demand, Constant Deterioration, Unit Production Cost, Without Shortage. MSC: 90B05. 306 P. Manna, S. Kumar Manna, Giri / An Economic Order 1. INTRODUCTION It is observed that the life cycle of many seasonal products, over the entire time horizon, can be portrayed as a short period of growth, followed by a short period of relative level demand, finishing with a short period of decline. So, researchers commonly use a time-varying demand pattern to reflect sales in different phases of product life cycle. Resh et al. [19], and Donaldson [7] are the first researchers who considered an inventory model with a linear trend in demand. Thereafter, numerous research works have been carried out incorporating time-varying demand patterns into inventory models. The time dependent demand .
