In this tutorial task, you'll learn how to create custom loading and unloading times for different types of flow items. You'll begin the tutorial task by changing the arrival schedule so that the upper floors regularly produce dirty laundry and waste that needs to be transported to the loading dock area. In the last step, you'll learn how to use a global table to create custom loading and unloading times for each type of flow item.
When you are finished, your simulation model will look similar to the following image:
In this step, you'll add additional activities to the DeliverySchedule process flow you created in an earlier tutorial task. Eventually, these new activities will create the logic that will regularly create dirty laundry and waste in the queues on each of the upper floors.
When you're finished, your process flow should look similar to the following image:
For now, you'll merely add and connect these activities to the process flow. You'll edit the properties to add the functionality in a later step.
To add and connect these activities:
|Source||Source: Simulation Starts|
|Create Object||Create Object: Item on Upper Floors|
|Delay||Delay: Collection Time|
Check that your process flow looks similar to the image shown in the beginning of this step.
In this step, you'll create the logic for the new activities you added in the previous step. The following is an overview of how each activity and shared asset will function:
|Source: Simulation Starts||This activity will create 3 tokens that will loop continuously throughout the rest of the activities in the Dirty Laundry shape. You'll assign a unique value for a label named Destination on each token. One token will create tokens for the Floor2DirtyLaundry queue, another for the Floor3DirtyLaundry queue, etc. You'll also offset the timing of some of these tokens so that they don't all move to the next activity at the same time.|
|Create Object: Item on Upper Floors||You'll edit this activity so that it will create the new DirtyLaundry flow item and place it inside the one of the queues on the upper floor. The token will use its Destination label to know which queue it should use. You'll also add a label named LoadType to the new flow items that will indicate which type of flow item it is. You'll use a value of 3 for DirtyLaundry flow items.|
|Delay: Collection Time||The token will be delayed a varying amount of time, representing the amount of time it takes a staff member to collect the dirty laundry. You'll use an exponential distribution with a scale of 1800 seconds (equivalent to 15 minutes). After the token finishes the delay, it will loop back to the Create Object activity.|
After you've made these edits, you'll create a copy of these activities that will simulate Waste collection. You'll make a few edits to the activities:
|Source: Simulation Starts (Waste)||This schedule source will be identical to the Dirty Laundry schedule source. The only difference is you will add a small offset time of 900 seconds to this activity. You'll also assign Destination labels that will create tokens for the Floor4Waste queue, the Floor3Waste queue, etc.|
|Create Object: Item on Upper Floors||You'll edit this activity so that it will create the new Waste flow item and place it inside the UnloadingDock queue. You'll also edit the LoadType label to use a value of 4 for Waste flow items.|
To create this logic:
Floor2DirtyLaundryin this cell.
Consider saving your simulation model at this point.
In this step, you'll add a second queue to the loading dock area. One queue will collect dirty laundry for shipment to a cleaning facility and one queue will collect waste for removal. You'll change the drop off logic so that the two queues in the loading dock area pull the dirty laundry and waste flow items from the ItemsReadyForDelivery global list. Because items in the upper floors will now need transport to the loading dock, you'll also add Next Look For Work connections from the main AGV network to each of the upper floors.
To change the drop off logic:
Reset and run the simulation model:
As the model runs, dirty laundry and waste will gradually appear in the queues on the upper floors and the AGVs will transport those items to the first available queue in the loading dock area.
In this step you'll create a global table that will control the loading and unloading times for the AGVs depending on what type of load they are transporting. When you're finished, your global table will look similar to the following image:
After setting up the global table, you'll then update the AGVs in the 3D model to use this global table to determine the loading and unloading times of the four different flow items. This step will demonstrate two different methods for referencing a global table. For the Load Time property, you'll learn how to reference a global table using a picklist. For the Unload Time property, you'll use a different method in which you'll reference a global table using FlexScript. Explore both methods to determine which one you prefer.
To customize the load times:
|Row Number||Row Name|
|Column Number||Column Name|
Reset and run the simulation model:
As the simulation model runs, you'll notice that the AGVs will spend different amounts of time loading and unloading flow items based on which type of flow items it is.
Now that you've completed the AGV tutorial, you hopefully have a good sense of all the different features and settings that are available when building an AGV model. As you can see, you've been able to build a fairly complex AGV simulation model using almost no code at all. The AGV features and process flow templates make it easy to build AGV systems and scale well to large simulation projects as needed.
For even more information about modeling AGV systems in FlexSim, consider reading the chapter about Working With Task Executers, which contains a section about AGVs. This concludes the AGV tutorial.