Raising the level of management from the enterprise level and improving its functioning to the level of the entire supply chain necessitates detailed planning of the flow of goods between all links in the chain. An additional difficulty in the field of supply chain management is the fact that many new concepts regarding the functioning of enterprises in this chain, although requiring decisions at the operational level, can only be evaluated in the long term.
Classic analytical models, still used to support the planning of goods flow, are no longer detailed enough for the needs of coordinating product flow between supply chain links. Increasingly, simulation is being used to analyze processes occurring in supply chains. A new, frequently used approach in the simulation analysis of product flow in the supply chain is the interactive approach. It allows for detailed tracking of all quantities characterizing the analyzed chain configuration and the volumes of flows between links. Furthermore, thanks to special user interfaces, it enables human teams to participate in the simulation.
Structure of the simulation system
The system has been designed in such a way as to enable the simulation of key business processes carried out in all links of the logistics chain. The basic objects in the system are: node, product, and vehicle. A node defines the geographical location of a supply chain link, as well as its maximum capacity. A product is an object that represents goods transported between nodes. A vehicle corresponds to the means of transport used to move products between locations. The system distinguishes four groups of nodes:
• supplier – carries out deliveries of goods
• producer – carries out the transformation of products into other products
• recipient – orders and receives products
• operator – corresponds to the base of a department or shipping company.
Figure 1 shows an example structure of a supply chain in which flows can be simulated using the described system. One supply chain link can be reflected in the system by one or several nodes belonging to different groups. The range of functions performed by the simulation system in each link depends on the types of nodes at a given location. The flow of products between links is possible only when directly cooperating nodes belong to appropriate groups. For example, a link that is not a supplier cannot supply a recipient, and the transport of goods can only take place with the involvement of an operator-type node. Additionally, vehicles are assigned to operator-type nodes (each vehicle to exactly one node). During the execution of a delivery, a vehicle must start and end its route at the node to which it is assigned.
The article comes from the magazine “Logistyka” No. 5/2007.