This paper investigates the dynamic inventory model for the case when production in a period is restricted to a finite set of specified values. The model allows the production rate to be any value in the set {0, P, 2P, ..., mP}, where m is a nonnegative integer. It is assumed that the setup cost...

We present structural and computational investigations of a new class of weak forecast horizons - minimal forecast horizons under the assumption that future demands are integer multiples of a given positive real number - for a specific class of dynamic lot-size (DLS) problems. Apart from being...

In this paper we consider the capacitated lot-sizing problem (CLSP) with linear costs. It is known that this problem is NP-hard, but there exist special cases that can be solved in polynomial time. We derive a backward algorithm, based on the forward algorithm by Chen et al. (1994), to solve the...

This work aims at investigating the influence of picking batch size to average time in system of orders in a one-aisle warehouse under the assumption that order arrivals follow a Poisson process and items are uniformly distributed over the aisle's length. We model this problem as an M/G[k]/1...

An approximation for the fill rate, i.e. the percentage of demand being delivered from inventory on hand immediately, is derived for items in a periodic review inventory control system with lost sales. We assume demand is stochastic and discrete, lead times are positive and replenishments are...

A single-machine multiproduct manufacturing system with random breakdowns and random repair times is considered. Under a weak capacity condition on the system it is shown that the total work-in-progress (WIP) is a recurrent stochastic process. By replacing the stochastic model by a deterministic...

A single machine processing different types of parts is considered. Switching from one type to another involves a setup time. The part types may have different processing times. The resulting scheduling problem is treated as a dynamical system for which several feedback policies that are...

Two heuristics based on branch and bound (B&B) are developed to solve closed-loop material requirements planning (MRP) lot-sizing problems that have general product structures and variable costs. A “look ahead method'’(LAM) heuristic allows for variable production/purchasing costs and uses a...