What happens if the Activity is busy and there is no buffer to receive an incoming item?
The item will wait in the last upstream residence block until the Activity block (Item library) can receive it. Residence blocks are any block that can hold an item for a non-zero amount of time. Examples include queues, activities, resource blocks, and some decision blocks. If the last residence block is a generator type block, the item will be held until a new item is created or the activity pulls the item. This is the only time that an item will be destroyed if there is downstream capacity.