In this step, you define possible reasons for ordering. These describe why a purchase order was placed. You can enter the reason for ordering in the item data when creating or maintaining a purchase order. The "reason for ordering" can also be used to document the reason for returning goods if the item in question is a returns item.
A typical reason for the creation of a purchase order may be "New business contact following attendance at a trade fair". Returns may be due to suppliers recalling parts or quality deficiencies you have discovered yourself.