We propose a model where customers are classified into two groups: short lead-time customers who require the product immediately and long lead-time customers to whom the supplier may deliver either immediately or in the next cycle. Unmet orders are backlogged with associated costs. Specifically,...

We consider the reorder point, order quantity inventory model where the demand, D, and the lead time, L, are independently and identically distributed (iid) randiom variables. This model is analytically intractable because of order crossover. However, we show how to resolve the intractability by...

We establish the computational complexity of the problem of minimizing makespan in a flowshop, where each jobs requires a pallet the entire time, from the start of its first operation until the completion of the last operation. We prove that the problem is NP-hard in the strong sense for m =2...

Flow shop scheduling is common in modern lean production systems. In practice, jobs in flow shops can arrive at irregular times. However, scheduling that considers such irregularity has not been adequately investigated in the literature. In this paper, we examine the scheduling of n-jobs in an...

A heuristic procedure is developed for minimizing makespan in flow-shop scheduling problems. In comparison with current algorithms, our algorithm seems to result in an improved makespan with a small additional computational effort. An algorithm is also developed to minimize the required number...

We consider the problem of scheduling n jobs in a pallet-constrained two-machine flowshop so as to minimize the makespan. In such a flowshop environment, each job needs a pallet the entire time, from the start of its first operation until the completion of the last operation, and the number of...

We study the problem of scheduling a chain-reentrant shop, in which each job goes for its processing first to a machine called the primary machine, then to a number of other machines in a fixed sequence, and finally back to the primary machine for its last operation. The problem is to schedule...

This paper improves upon the existing literature surrounding the production order quantity inventory model in which unit cost and daily production are assumed to be constant. By including economies of scale into the model, we examine its impact on production order quantity and total cost. The...

Inventory control is among the most important topics in operations research because of large investments in inventory and their effect on the profitability of the firms. A systematic analysis of inventory problems began with the development of the classical EOQ formula of Ford W. Harris in 1913,...

In this paper we develop a combined inventory-transportation system. The general idea is to integrate a simple replenishment policy with a routing component to derive operationally consistent standard routes as a basis for milk run design. The most interesting feature of the approach is that we...