Draft #
When created, a purchase order is in the Draft status.
Possible transitions: issued, canceled.
Issued #
Possible transitions: closed, canceled.
Closed #
A purchase order in the Issued status can be set to the Closed status. Once the purchase order is closed, however, it is possible to reopen it: it returns to the Issued status.
Possible transition: issued.
Canceled #
It is possible to cancel a purchase order as long as it is not in the Closed status. Once the purchase order is canceled, it is no longer possible to modify it.
Possible transition: none.