## 5 Applications of the General Vehicle Routing Model in Case of Out-Plant Material Handling
### Transport of Parcels  
The transportation of parcels is also a completely different case. The number of levels can be important here, especially for foreign parcels. From the post office, the parcels are sent to a central sorter, then to other sorters, then finally to a post office close to the recipient, and finally from there to the recipient. A multi-level satellite system was considered in this case.  
Among the attributes between nodes, the followings are important: travel time between the locations, travel distance between locations, and route status between the locations.  
Different types of vehicles (land, water, air) can also be used. It also depends on the levels, and what kind of vehicles is used. Attributes for vehicles are also important; here too we need to consider several attributes. Several types of vehicles can be used, so these attributes are very important: capacity constraint of each vehicle, fuel consumption of vehicles and recharger time can also be calculated because electric vehicles can also transport mail items. Whether the vehicle is owned or borrowed can also be an important factor. The rental fee per vehicle type is also an important factor when using rented vehicles. Fuel consumption of vehicles can also be a useful factor.  
The packing time of the locations is low; letters are only bagged, just as the unpacking time of the locations is low. However, there is a loading time for the locations, as well as an unloading time of the locations. The fuel filling time of the vehicles can be considered. There is also a time window; each sending post office has opening hours, which can vary depending on the size of the post office. Each sorting location may also have opening hours.  
A multiple-time window can also be used; each post can close e.g., due to a lunch break in the village post offices.  
In terms of the functional parameter, the soft time window can also be used, e.g., the post office receives letters and parcels even after it is open, but then the postmen must pay overtime, so the objective function gets a penalty point. The open route can also be used, especially in the case of transport by train, boat, or plane, and in the case of road transport, round-trip transport is common.  
Among the metrics, the minimization of the route is an important factor. Profit maximization is not usually used, so minimizing sold values, minimizing packaging costs, minimizing unpacking costs, minimizing loading costs, minimizing unloading costs, minimizing administrative costs, and minimizing quality control costs do not make sense. Minimization of fuel consumption and minimization of the vehicle rental fee can be considered. Maximization of road safety is not usually considered but maximizing route status can be considered. From the time minimization factor, the minimization of route time can be considered, but the minimization of packaging time and minimization of unpacking time factors does not make sense. minimization of loading time can be useful, but minimization of capital time has no sense. Minimization of administrative time and minimization of quality control time is not considered. Of the penalty points, exceeding the number of suppliers and unvisited customers can be important, because it is important that all customers are served by a given vehicle.  
The test run included the following parameters: products (postal package). The result was the following vehicle list: truck, train, vehicular vehicle, and airplane.  
The validation of the test run was the following: the test result was correct; these classes contain many subclasses covering a wide range of vehicle types.