Organization of transport routes in the tasks of storage, distribution and supply of resources with the optimization model MILP

• Date: 2023
• Main Author: Кузьмичов, А. І.
• Format: Article
• Language: Ukrainian
• Published: Інститут проблем реєстрації інформації НАН України 2023
• Subjects: network organizational structures; network optimization modeling; transport logistics; supply chains; spreadsheet modeling; optimization methods and models in Excel
• Online Access: http://drsp.ipri.kiev.ua/article/view/300773
• Journal Title: Data Recording, Storage & Processing

The vehicle routing problem (VRP) is concerned with optimizing a set of routes, all beginning and ending at a given node (called the depot, center park or warehouse), to serve a given set of customers. The VRP was first introduced by Dantzig and Ramser (1959). It is a multivehicle version of the traveling salesman problem (TSP), and is therefore more applicable in practice since most organizations with substantial delivery operations use multiple vehicles simultaneously. Of course, it is also more difficult than the TSP since it involves decisions about how to assign customers to routes, in addition to how to optimize the sequence of nodes on each route. As a result, today’s «hard» VRP instances tend to involve, say, hundreds of nodes, whereas hard instances of the TSP involve thousands or tens of thousands of nodes. The VRP is used to model, in which a single vehicle delivers goods to multiple customer nodes with returning to the depot. The vehicle routing problem is a combinatorial optimization problem of integer programming. The goal: to organize an optimal set of local vehicle routes, several or one, according to their number, configuration and loading, to minimize the total transport costs for the delivery of orders from a single center to customers at their given location coordinates. VRP is a typical component of transport logistics and supply chains, the sphere of providing services for current maintenance of objects, prompt repair and elimination of accidents in network organizational structures. To solve this problem, the MILP model was developed and tested on specific examples using available Excel analytical tools in educational and research practice. The classic VRP (with orders) has a strictly decreasing sequence of flow values, which is relatively easy to divide into a certain number of subcircuits with the same decreasing sequence depending on the value of the TK potential. However, a VRP with customer resource reserves cannot have such a sequence, there is a simultaneous increase and decrease of current values in the chain of flows, so a single circuit is possible here by choosing a sufficient potential of TK, or, depending on the situation, the formation of several artificial sub-circuits from unreached groups of nodes. Fig.: 9. Refs: 8 titles.