Oracle scm purchase order-status & document security rules

Purchase order statuses

INCOMPLETE- whenever you open PO form status should be incomplete until you click the                                          approve button  

IN PROCESS- when you click the approve button status going to In process until approver approve                               the PO 

APPROVED- when approver approved the PO status going to approved

REQUIRES RE APPROVAL-- when we made any changes on approved PO status going to requires                           re-approval. document goes to approval again. we need to be approve the PO

REQUIRES RE APPROVAL, ON HOLD-- when approved PO applied any hold status going to requires re-approval on hold. we need to release the hold. once release the hold status going to requires re-approval again we need to approve it. but this time it wont go to any approver

APPROVED, CLOSED- when you closed approved PO status going to approved, closed. even-though its closed PO we can able to open it

REJECTED- when approver did the document reject status going to be rejected

CANCELED PO--when purchase order has canceled closure status going to be closed
                              if we do finally closed for canceled PO closure status going to finally closed

when the PO document having these statuses like FROZEN, CANCELED, FINALLY CLOSED, INCOMPLETE, IN PROCESS, PRE-APPROVED
we can't able to open those PO's
-----------------------------------------------------------------------------------------------------------

when document having security rule

if you unchecked the APPROVER CAN MODIFY check box in document type
did security level: PRIVATE
access level: VIEW ONLY 

security rule: PRIVATE
access level: MODIFY

security level: PRIVATE
access level: FULL

security level: HIERARCHY
access level: VIEW ONLY 

security rule: HIERARCHY
access level: MODIFY

security level: HIERARCHY
access level: FULL

security level: PURCHASING
access level: VIEW ONLY 

security rule: PURCHASING
access level: MODIFY

security level: PURCHASING
access level: FULL

when document having these security & access rule when approver can modify check box uncheched

approver can't able to modify the document when approver gets the PO

APP-PO-14694 updates couldn't possible