When you add an item to a stock request, you can have the stock request automatically issue the stock item. To do this, you need to make sure that you have turned on Auto-issue request items in the Stock Module Defaults window Other tab.
When you add an item to a request, Pinnacle will check that the auto-issue flag is turned on. If it is, then Pinnacle will check that the stock item has a preferred location, and that the preferred location has enough stock available to meet the issue.
If those conditions are met, Pinnacle will automatically add an issue for the stock item to the request.