A new order is placed when the input queue of an activity, or the contents of a storage, falls to the re-order level specified in the Order Signal. The activity’s input queue, or the storage’s contents must first reach a level higher than the re-order level, then fall to that level, or an order will never be placed. Therefore the size of the activity’s input queue or storage’s capacity must be at least 1 larger than the re-order level.
Suggested Technique
- Create an ordered arrival connection from the entity to be ordered to the activity or storage where it enters the process.
- Connect the storage or activity where the inventory level is to be monitored to an ordered arrival or routing connection.
- Select the Order Signal connection and enter the Reorder level and the Order quantity in the properties dialog.
- Check Place order at start if you want an order to be placed at time zero of the simulation. (This is useful in initializing the inventory at the activity or storage.)
Example: A storage area containing a box of clear plastic bags is used in the packaging line for shipping computers. When there are 30 bags left, 100 more bags are ordered.
TO DO: Create the Ordered arrival connection from Part A to the Storage Bin. Connect the Storage Bin to the Ordered arrival. For the Order Signal, enter 30 and 100 in the Reorder level and Order quantity fields as shown above. Set the input queue of Assembly1 to zero.
If a storage immediately follows the end point of the Order Signal (where the order arrives), the free capacity of the storage must be equal to or greater than the order quantity. If an activity immediately follows the order arrival point, the sum of the activity’s input queue and capacity must be equal to or greater than the order quantity.