We develop the first algorithmic approach to compute provably good ordering policies for a multi-period, capacitated, stochastic inventory system facing stochastic non-stationary and correlated demands that evolve over time. Our approach is computationally efficient and guaranteed to produce a policy with total expected cost no more than twice that of an optimal policy. As part of our computati...

a new mathematical model for the optimal production isformulated for the inventory management system under time-varyingand stochastic inflation environment for deteriorating items. the timehorizon is finite and demand rate is dependent to the inflation. in thereal situation, some but not all customers will wait for backlogged itemsduring a shortage period, such as for fashionable commodities or...

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...

In this paper, we introduce a generalization of the continuous mixing set (which we refer to as the continuous n-mixing set) Qm,n := {(y, v, s) ∈ ( Z× Zn−1 + )m×Rm+1 + : ∑nt=1 αty t + vi + s ≥ βi, i = 1, . . . ,m}. This set is closely related to the feasible set of the multi-module capacitated lot-sizing (MML) problem with(out) backlogging. For each n′ ∈ {1, . . . , n}, we develop a class of va...

This paper proposes tools which will be used to optimize multi-level assembly under lead time uncertainty. One type of finished products and several types of components are considered. We suppose that each component has a fixed unit inventory cost and the finished product has backlogging and inventory holding costs per unit of time. The lead times of components are discrete random variables, an...

This paper deals with a two-warehouse inventory model for deteriorating items with time dependent demand and partial backlogging under inflation. It is assumed that deterioration of items follows two-parameter Weibull distribution and demand rate varies exponentially with time. Shortages are allowed and partial backlogging depends on waiting time of next replenishment. A numerical example is pr...

This paper presents a simple deterministic EOQ with time-dependent partial backlogging. The penalty during stockout arises from lost sales rather than from the usual shortage cost parameter. The model has a unique minimum for a broad class of lost-sales behavior during stockout. The main result is that a special case corresponds to the traditional full backlogging model and provides a means to ...

This paper examines an economic production quantity (EPQ) model with rework and service level constraint. First, we prove that the expected overall costs for an imperfect EPQ model with backlogging permitted is less than or equal to that of the one without backlogging. Secondly, the relationship between “imputed backorder cost” and maximal shortage level is derived for decision-making on whethe...

We consider an infinite horizon production planning problem with non-stationary, convex production and inventory costs. Backlogging is allowed unlike related previous work and inventory cost is interpreted as backlogging cost when inventory is negative. We create finite horizon truncations of the infinite horizon problem and employ classic results on convex production planning to derive a close...

The deal for industrial companies is to satisfy their customers with the best quality, the most reliable lead times, and the lowest costs. One of the keys to achieve it is in the inventory control in the Supply Chain. Moreover, it is mandatory to possess necessary components in order to produce the requested products by the due date. But, as the components lead time is an unpredictable paramete...