The document outlines the steps for processing an outside purchase from the parts counter when a part is out of stock. It involves looking up the part, determining it is unavailable, selecting the option to source it from an outside vendor, entering the details of the purchase, creating a purchase order, checking out the customer, and receiving the part when it arrives. It emphasizes using the proper payment type of PCard to avoid issues and recording a lost sale to help buyers stock more demanded parts.