Purchasing allows you to control the status of your requisitions, planned and standard purchase orders, blanket and contract purchase agreements, and releases during the document life cycle. Purchasing provides you with the features you need to satisfy the following basic needs. You should be able to:

• Delete unapproved documents or unapproved lines, shipments, and distributions that you add to previously approved documents
• Terminate existing commitments to buy from suppliers by fully or partially cancelling your documents
• Control how Purchasing automatically closes documents for receiving and invoicing activity
• Indicate that no further internal activity is expected or allowed on completed orders by final closing them
• Freeze or unfreeze documents to control whether modifications are allowed
• Place documents on hold to prevent printing, receiving, invoicing, and approval until the hold is removed
• Firm purchase orders to prevent Oracle Master Scheduling/MRP and Supply Chain Planning from suggesting reschedules in, cancellations, or new planned purchase orders within the time fence created by your firm date

Document Security determines the documents on which you can perform control actions.
If the document is a global agreement, the Manage Global Agreements function security determines if you can perform control actions.