Provides and stores stockroom items such as raw materials, work in process, and so on. This block may be used in an open system such as when items are shipped, or in a closed system such as when you exchange parts in spares inventory. Items can be pulled from the output as long as there are items available. You can add attributes and priorities to items passing through the block.
The change connector is usually used to change the number of items available in the stock by the value of the item input at change. The only difference between the regular item input connector and the change connector is that the change connector can cause the number of items available to be reduced. You can set an initial number of items in the dialog. When the number of items in the block reaches 0, no more items can be pulled from the block until the number becomes positive.
The dialog and the # connector report how many items are in the block. The use connector tells the number of items that are in use at any particular time. To determine the utilization, divide the value of the use connector by the sum of the value of the use connector and the value of the # connector: use/(use+#).
The default for the resource blocks is to strip away all attributes on items coming into the input connectors.
Dialog Choices
Display items available: Number of items in the stock at the current time.
Initial number: Starting number of stock items.
Name: Name of the default attribute.
Priority: Priority for the item.
Strip attributes from incoming items: Removes attributes from items coming in the input connectors. This is the default. You would usually select this if modeling a closed system.
Utilization: The percentage of time the Stock was in use (out of the Stock block) over the course of the simulation run. Note that this statistic only makes sense in a closed system where the Stock is cycled back to the Stock block.
Value: Value for the default attribute.
Connectors
The input is an item.
The output an item.
#: Number of items available in the stock.
change: When the change connector pulls in an item, it changes the number of items in the stock by the value of the item. This works the same as the item input connector, except that the value of the item can be negative, reducing the number of stock items available.
use: Number of stock items in use in the model which have not been returned to the block.
Animation
Flashes when an item arrives and when an item leaves, and shows the number of items available in the block.
