Hi Prasad
In Ful- wip and variances can't co exist. Wip and variances depend on order status I.e. Dlv and teco.
In Per - order status is not important and both things can co exist.
System design with PER is that all orders are pulled up in month end processes till the time they are closed. So you should ideally assign Clsd status to them once completed
In 2008 sap released a sap note on one of my oss message after which the behaviour changed and prod orders are pulled up only if some action has happened on them
You can raise oss message and ask sap. The note was in a pilot phase then
Ajay M