I have been told that one I assign a Unit of Measure to a material of EA (each) all quantities for Requirements, Orders, and Inventory must be in integers. This may also be true for a UOM of PC (pieces).
If fractional quantities are needed/stored/shipped then it would make sense to use another UOM. Since you cannot change a Base Unit of Measure once it has been assigned, this decision is critical.
If the use of fractional quantities is controlled thru Configuration, then I would like to know which transaction should be used to set this control - and if it can be changed, once assigned.