GP Extension Purchase Order module helps you to track your company’s purchasing activity. You can enter and manage purchase orders, track shipments and invoices received

Dynamics GP allows you to control vendors and maintain a secure database of approved vendors

The same vendor master file is used for payables and purchasing, and has a nice integration to inventory to make sure there is a manged relationship between an item and vendors that are approved to supply the item.

You can maintain an unlimited number of vendor addresses for any vendor. You can attach key documents (e.g. contracts) to the vendor masterfile. You can maintain various types of payment terms and assign them to vendors as a defaults.