TY - JOUR T1 - Probabilistic Periodic Review (Qm, N) Backorders and Lost Sales Inventory Models under Constraint and Varying Holding Cost and Normally Distributed Protection Interval Demand AU - Aly Fergany, Hala AU - Hassan El-Sodany, Naglaa JO - Journal of Modern Mathematics and Statistics VL - 5 IS - 3 SP - 71 EP - 79 PY - 2011 DA - 2001/08/19 SN - 1994-5388 DO - jmmstat.2011.71.79 UR - https://makhillpublications.co/view-article.php?doi=jmmstat.2011.71.79 KW - Probabilistic periodic review inventory system KW -varying holding cost KW -review cost KW -protection interval demand KW -Backorders inventory model KW -Egypt KW -Lost sales inventory model KW -Lagrangian multiplier technique AB - This study derives the probabilistic periodic review Backorders and Lost sales inventory models when the holding cost is a function of the inventory cycle. The expected total cost is composed of four components; the expected purchase cost, the expected ordering cost, the expected reviewing cost, the expected holding cost and the expected shortage cost. The objective is to minimize the expected annual total cost under a restriction on the expected annual reviewing cost when the protection interval demand follows the normal distribution. The Lagrangian multipliers are used to solve this constrained model in a closed form. Finally, some special cases are deduced and an illustrative numerical example is added with some graphs. ER -