Adding Route Parameters into the Model
As you will recall from the lecture videos, Modeling Network Paths, the route is more than just a path. In a vehicle routing model, routes are a network class that defines the vehicle, the driver, and the linear features they travel on. Routes also have attributes that influence cost or place limitations on the model. In this model, our routes have attributes that include the depot where the route will start and end. The starting and ending service time attributes indicate the time it takes to prepare and service the garbage trucks at the start and end of each day. The earliest and latest start time attributes indicate the time window when the route will first begin. Routes also have attributes related to the vehicle. The capacities attribute indicates the carrying capacity of the garbage truck before it needs to be emptied. In this scenario, a side-loading garbage truck can carry twenty thousand pounds before it needs to be emptied. When the model runs, this attribute will be compared to the pickup quantities attribute of the Orders to determine when the truck is full. The model assumes that both the capacity and the pickup quantities use the same unit of measurement. The cost per unit distance attribute defines the operating cost of the vehicle per mile, including fuel and maintenance. Finally, routes have attributes related to the driver. These attributes include driver salaries, as dollars per minute, under the cost per unit time value. The overtime start and cost per unit overtime tracks when any overtime pay accrues. The max total time attribute defines the maximum length of time a single driver can work. In this scenario, the total number of hours a driver can work is limited to twelve hours. Right click on Routes in the Network Analyst window and select Add Item. This opens up the Route Properties window.
Under the Value column, enter the following values in the Route Properties window. Keep the default values for any properties not listed here.
|StartDepotName||Eureka Garbage Dump|
|EndDepotName||Eureka Garbage Dump|
Once the values above are entered, click OK. The routes should now be loaded in two places. The routes in the Network Analyst window represent our model parameters. Any modification of the model parameters, or input to the model, are entered here. In the Table of Contents, the memory feature class, also named Routes, is now populated with the route attributes, the output from the model. Next, you will add a Route Renewal into the model.