Where to find the item-level attribute Shortage Tolerance Percent

In reading up on this feature, I see that there are some profiles which would apply generally to all items, and there is the opportunity to simulate planning with shortage tolerances set at the item level - using item mass maintenance.  Item level settings are what we need.

http://docs.oracle.com/cd/E18727_01/doc.121/e13358/T309464T309478.htm#suptol

I can't find any reference to this attribute on the item master source. Surely we aren't to use a simulation set for permanent attribute settings, are we?

Can someone help me spot it?

Thanks,

John