In this paper, an purchasing inventory model for deteriorating items is developed with a linear, positive trend in demand, allowing inventory shortages and backlogging. It is assumed that the goods in the inventory deteriorate over time at a constant rate . Two models are developed for two operational policies. The first policy covers the case that the inventory model with linear demand for det...

Inventory control is considered one of the most widely documented topics in reality. Fractional derivatives and integration part fractional calculus. calculus generalized ordinary The memory physical phenomena a highly concerning topic but it neglected with describing terms integer-order differential equation. To discuss inventory model, derivative tools are considered. A at any point gives pre...

This paper presents a discounted cash-flow approach to an inventory model for deteriorating items with the &#10two-parameter Weibull distribution. According to our proposed model, two shortages are considered: back-orders and lost-sales, &#10in which the back-order rate is a varying function of the time when the shortage happens. In general, the demand rate is a linear function of the selling p...

The fill rate is usually computed by using the traditional approach, which calculates it as the complement of the quotient between the expected unfulfilled demand and the expected demand per replenishment cycle, instead of directly the expected fraction of fulfilled demand. Furthermore the available methods to estimate the fill rate apply only under specific demand conditions. This paper shows ...

This paper presents a discounted cash-flow approach to an inventory model for deteriorating items with the two-parameter Weibull distribution. According to our proposed model, two shortages are considered: back-orders and lost-sales, in which the back-order rate is a varying function of the time when the shortage happens. In general, the demand rate is a linear function of the selling price...

this paper investigates an epq model with the increasing demand and demand dependent production rate involving the trade credit financing policy, which is seldom reported in the literatures. the model considers the manufacturer was offered by the supplier a delayed payment time. it is assumed that the demand is a linear increasing function of the time and the production rate is proportional to ...

The aim of this study was to explore the reasons behind medicine shortages from the perspective of pharmaceutical companies and pharmaceutical wholesalers in Finland. The study took the form of semi-structured interviews. Forty-one pharmaceutical companies and pharmaceutical wholesalers were invited to participate in the study. The pharmaceutical companies were the member organizations of Pharm...

This study proposes an EOQ inventory mathematical model for deteriorating items with exponentially decreasing demand. In the model, the shortages are allowed and partially backordered. The backlogging rate is variable and dependent on the waiting time for the next replenishment. Further, we show that the minimized objective cost function is jointly convex and derive the optimal solution. A nume...

A fuzzy inventory model with price dependent demand is considered. The shortages are allowed . The objective is to determine the optimal total cost and the optimal time length of the plan for the proposed model. The trapezoidal fuzzy numbers are introduced to achieve this objective. The signed distance method is used for defuzzification process. To illustrate the results of this model, sensitiv...