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...

In this paper, an inventory model with ramp type demand rate with inflation and time value of money is developed. The deterioration rate follows three-parameter Weibull distribution with the concept of life time of an item. Shortages are also allowed and unsatisfied demand is partially backlogged. The model is fairly general in practice, as the demand of some items such as fashionable items inc...

In this paper, the traditional inventory lot-size model is extended to allow not only for general partial backlogging rate but also for inflation. The assumptions of equal cycle length and constant shortage length imposed in the model developed by Moon et al. [Moon, I., Giri, B.C., Ko, B., 2005. Economic order quantity models for ameliorating/deteriorating items under inflation and time discoun...

In real world, some manufacturing companies may encounter the production restriction. For instance, if the number of products increases, given company may not be able to produce all products. Therefore, it may encounter the backlogging. On the other hand, if product demand increases, given company may encounter restricted capacity to respond to such demands; so, it will also encounter backloggi...

In this paper, we consider the well-known constant-batch lot-sizing problem, which we refer to as the single module capacitated lot-sizing (SMLS) problem, and multi-module capacitated lot-sizing (MMLS) problem. We provide sufficient conditions under which the (k, l, S, I) inequalities of Pochet and Wolsey (Math of OR 18: 767-785, 1993), the mixed (k, l, S, I) inequalities, derived using mixing ...

In this article, we study an inventory system for items that have a power demand pattern and where shortages are allowed. We suppose only fixed proportion of during the stock-out period is backordered. The decision variables cycle ratio between initial stock total quantity demanded throughout cycle. objective to maximize Return on Inventory Investment (ROII) defined as profit per unit time over...

This paper addresses the problem of determining the sale price and the production quantity under supply uncertainty. The problem is commonly observed in the agricultural industry. We consider a firm that initially leases farm space in order to grow fruit. The realized amount of fruit supply fluctuates due to weather conditions, diseases, etc. At the end of the growing season, the firm makes two...

Lot sizing and scheduling in flow shop has been considered in this paper. Our study includes a multi-level and multi-period capacitated lot sizing and scheduling problem (CLSP) with sequence-dependent setups, setups carry over in flow shop. In manufacturing environments backlogging is unavoidable. If the production capacity is infinite, any demand can be satisfied

Keqi Yan: Fluid Models for Production-Inventory Systems (Under the direction of Professor Vidyadhar G. Kulkarni) We consider a single stage production-inventory system whose production and demand rates are modulated by a finite state Markov chain called the environment. Supplementary orders can be placed from external suppliers when needed. We model this system by a fluid-flow system and derive...