production planning and scheduling are the most important issues of the production industries, which have a considerable influence on the productivity of the production systems. although, production planning and scheduling are in two different medium-term and short-term decision making levels, there are a very close relationship between them. ignoring this important feature in production planni...

In this paper, a bi-objective multi-product (r,Q) inventory model in which the inventory level is reviewed continuously is proposed. The aim of this work is to find the optimal value for both order quantity and reorder point through minimizing the total cost and maximizing the service level of the proposed model simultaneously. It is assumed that shortage could occur and unsatisfied demand coul...

This paper focuses on a production scheduling problem in a tree-structured assembly system operating on a make-toorder basis. Due dates are considered as constraints in the problem, that is, tardiness is not allowed. The objective of the problem is to minimize holding costs of ®nal product inventory as well as work-in-process inventory. A mixed integer linear programming model is given and a br...

Inventory-routing problems (IRPs) arise in vendor-managed inventory systems. They require jointly solving a vehicle routing problem and an inventory management problem. Whereas the solutions they yield tend to benefit the vendor and customers, solving IRPs solely based on cost considerations may lead to inconveniences to both parties. These are related to the fleet size and vehicle load, to the...

The integrated production, inventory and distribution routing problem (PDRP) is concerned with coordinating the production, inventory and delivery operations to meet customer demand with an objective to minimize the cost. The particular PDRP that we consider in this study also involves heterogeneous transporters with non-instantaneous traveling times and many customer demand centers each with i...

tendency to optimization in last decades has resulted in creating multi-product manufacturing systems. production planning in such systems is difficult, because optimal production volume that is calculated must be consistent with limitation of production system. hence, integration has been proposed to decide about these problems concurrently. main problem in integration is how we can relate pro...

The single-item stochastic inventory control problem is to find an inventory replenishment policy in the presence of independent discrete stochastic demands under periodic review and finite time horizon. In this paper, we prove that this problem is intractable and for any 2 > 0, we design an algorithm with running time polynomial in the size of the problem input and in 1/2, that finds a policy ...

This paper deals with an optimal ordering policy for non-deteriorating item with power demand under trade credits. The shortages are allowed and combination of backlogged and lost sales. Mathematical model is developed under two different situations, i.e., case 1: the permissible delay period is less than time to finish positive inventory and case 2 trade credit period is greater than or equal ...