When editing an Inventoried part, there are two boxes that  are very helpful.

The first is the Max on hand.

This field is  used to determine the maximum number of this part you would like to have on hand at any given time.

It helps prevent from ordering too many of a particular part.

There is also a Reorder Level field that tells you how many of a part should trigger a new order.

For example, you might have 6 of a particular oil filter on hand. If your max on hand is 10 and your reorder level is 2, then when you reach 2 in your system it will trigger a new order. But it will only request that you order eight more to bring you to your maximum on an object