We present an improved implementation of the Wagner-Whitin algorithm for economic lot-sizing problems based on the planning-horizon theorem and the Economic- Part-Period concept. The proposed method of this paper reduces the burden of the computations significantly in two different cases. We first assume there is no backlogging and inventory holding and set-up costs are fixed. The second model ...

Inventory management is an important thing to be considered in order run the activities of a company smoothly. By considering deterioration factor, partial backlogging policy and different type demand functions, we develop mathematical model for multi-item inventory system. In this paper, three models with constant deterioration, backlogging, various functions are developed. We consider invento...

Harris’s classic square root economic order quantity (EOQ) model forms the basis for many other models that relax one or more of its assumptions. A key assumption of the basic EOQ model is that stockouts are not permitted. Due to the excess demands, stock-out situations may arise occasionally. Sometimes, shortages are permitted and they are backordered and satisfied in the very next replenishme...

A deterministic inventory model for infinite time-horizon incorporating inventory level-dependent demand rate, deterioration begins after a certain time, partial backlogging and decrease in demand is developed. The salient feature of the developed model is the introduction of the concept of fractional decrease in demand due to ageing of inventory. Demand at any instant depends linearly on the ...

This paper investigates the impacts inventory shortage policies have on transportation costs in base-stock distribution systems under uncertain demand. The model proposed demonstrates how backlogging arrangements can serve to decrease the variability of transportation capacity requirements, and hence the magnitude of transportation costs, when compared with policies that expedite demand shortag...

This paper considers a dynamic lot size problem faced by a producer who supplies a single product to multiple customers. Characterized by their backorder costs as well as shipping costs, the customer with a high backorder cost is the one whose need for the product is more critical than the need of a customer with a low backorder cost. We show that the general problem with time-varying, customer...

As a traditional model in the operations research and management science domain, deterministic lot-sizing problem is embedded in many application problems such as production and inventory planning and has been consistently drawing attentions from researchers. In this paper we consider basic versions of lot-sizing models in which problem parameters are stochastic and develop corresponding scenar...

Persediaan merupakan cadangan barang yang dikelola oleh setiap perusahaan untuk memenuhi permintaan pelanggan. Parsial backlogging terjadi saat persediaan mengalami kekosongan namun masih ada, akibatnya hanya sebagian pelanggan bersedia menunggu sampai tersebut tersedia. Permintaan terhadap cukup bervariasi karena dipengaruhi faktor cuaca, tempat lokasi dan lain-lain. Tujuan dari penelitian ini...

One of the basic assumptions of the classical dynamic lot-sizing model is that the aggregate demand of a given period must be satisfied in that period. Under this assumption, if backlogging is not allowed then the demand of a given period cannot be delivered earlier or later than the period. If backlogging is allowed, the demand of a given period cannot be delivered earlier than the period, but...

The practical experiences reveal that the inflation is non-deterministic and variable. Therefore, a mathematical model for the optimal production for an inventory control system of deteriorating items is formulated under time-varying and stochastic inflation environment. The demand rate is a function of inflation and the time horizon is finite. In the real situation, some but not all customers ...