| dc.description.abstract | This thesis study introduces the Inventory-Routing Problem (IRP) with multi
customer, multi- product and multi-period and direct shipping in a trading company.
This problem arises when inventory management and vehicle routing decisions should
be integrated simultaneously, which is typically the case in vendor-managed inventory
systems. The main objective of this paper is to center on solving the problem that the
company is facing and support the company to optimize their current process related
to inventory and transportation, so that it can achieve its target in the Key Performance
Indicators (KPI). Based on the literature review on inventory routing models, a
mathematical model which considers main constrains such as the distance among
nodes, customers’ capacity, beginning inventory level at customers, daily demand of
customers and trucks capacity is developed to minimize the total cost spent on
inventory holding and transportation. The model is solved by IBM CPLEX using the
actual data collected from the company to examine whether this approach is practical
in reality, giving optimal inventory levels at each customer’s warehouse, delivery
schedules with optimal shipped quantity. The findings of this study show a reduction
of 37% regarding optimal solution and 15.5% regarding inventory-based matheuristics
in the overall cost, demonstrating a positive impact on the company’s performance in
terms of inventory and routing. | en_US |
