it depends on your setup of the parameters for item planning. If no SKU is used, it means NAV treats each demand seperately. When SKU is used, user could set up a more centralized way of planning.
for example: for item ABC
location X: sku ABC x, replenish: transfer from y
location Y: sku ABC y, replenish: transfer from z
location Z: sku ABC z, replenish: purchase
let say there is no inventor of ABC and 2 is needed for X, 3 is needed for Y, 5 is needed for Z.
when NAV finds item ABC is needed, it create a purchase order for Z with qty of 10
then transfer order will be created to move items to X and Y per setup.
