Modelling network design and inventory routing problems with logistics collaboration and heterogeneous customer segment assumptions

Companies operating in complex industrial environments need to be in a continuous process of development to meet the increasing expectations of their customers and to survive in a competitive environment. In this context, the business relationships that companies establish with each other to improve their production and distribution processes form the basis of today's supply chains. Supply chain collaboration is a critical requirement for companies to maintain a competitive advantage and increase operational efficiency. Another important issue with potential benefits in supply chain management is customer segmentation. The ability to provide tailored services by focusing on the specific needs and preferences of different customer groups can increase customer satisfaction and loyalty. The first problem addressed in this thesis, the network design problem, involves heterogeneous customer segments with horizontal cooperation and a finite planning horizon, assuming demand uncertainty. The problem is formulated mathematically, including channel selection, distribution planning, inventory, replenishment, and allocation decisions. The inventory routing problem, which is the second problem considered in the study, is mathematically modelled under the assumption of demand uncertainty, with heterogeneous customer segments and cooperation between them, including channel selection, distribution planning, inventory, and replenishment decisions. A three-stage heuristic solution approach is proposed to solve the inventory routing problem. The heuristic solution approach aims to contribute to the solution of large-scale inventory routing problems more effectively. The results of the study highlight the strategic importance of heterogeneous customer segments and collaboration in network design and inventory routing problems. The study provides a detailed account of the benefits of establishing mutually beneficial collaborations, especially for companies that have complex distribution networks and serve different customer segments. The findings enable companies to develop more effective strategies in terms of sustainability, cost-effectiveness, and customer satisfaction. Keywords Network Design Problem, Inventory Routing Problem, Logistics Collaboration, Customer Segmentation, Uncertainty, Heuristic Solution Approach.