In most cases goods are received using the factory system however you can also perform this function using the main M-Power interface also as follows.
From the customer screen select Menu  then Inwards Goods .
Find the purchase order that you would like to receive goods against the click Receive .
You can then enter the supplier docket number if required , alter the qty if required  and finally click Receive . Note that the line will still show in the list until you refresh the view.