This is thesis concerned with the inventory has deteriorating character in aimed area as Republic of Yemen where the collected data of the study area consist of the two types of deteriorating items as first the deteriorating item which it has only the deterioration character second one the item has two characters as deterioration and break-ability rates simultaneously, so that there are many inventory models both first and second especially when the inventory level, not equal zero before any replenishment, the important thing the proposed models for inventory are developed in a general way for any inventory satisfied the assumptions and conditions. The developed inventory models are fitted for the inventory level for the deteriorating items as fruits (an orange, banana, apple, tomato), similarly, the item who is deteriorating and breakable, as Eggs, watermelon, any productions are being packed in the glass. The optimal total cost also EOQ and optimal time-run obtained in the assumed models also the shortage cost considered in two possibilities, if it is allowed or not allowed, the leading time also focused in the study when it is zero or non-zero to developed the inventory system with a general idea and try to apply it for the data which are collected from the area of the study. The estimation of the inventory level of the daily demand had by much software as SPSS, MINITAB, Easy fit, the allocation data might be considered as sensitivity analysis for the proposed models, as the applications of real life.
The calculation of the dependent variables as the total cost function, the optimal quantity and optimal time of run-time had by the Microsoft Excel, the investigations in this study achieved through the development the theoretical part in the inventory control system and their applications within real data and realistic assumptions. The real assumptions in the proposed models made the study add the contributions to the international marketing environment and the Yemeni marketing, the overall proposed models fitted for the inventory in the Republic of Yemen any inventories have the same characters in the following dependents variables as the daily demand or weekly, order quantity, the time-run for new replenishment for the stocks. The deterioration rate is an important variable in the study and the proposed models with range lie between zero and one, all types of cost associated with the inventory. The independent’s variables as the time of demand forming the goods from the stock. The output of purposed models is merits for the developed model related to the explanation of the relationship between the deterioration and economic order quantity.