Explanation
You must run the Track Purchasing Activity process to display information about the status of purchase orders or agreements created in Oracle Fusion Purchasing on the contractfulfillment's Purchasing Activity tab.
References:https://docs.oracle.com/cloud/farel8/procurementcs_gs/FASCA/F1174615AN1AFD6.htm

Explanation
How can I change the due dates, notifications, and other contract deliverable details?
You can change the due dates,notifications, and other contract deliverable definition details in the Deliverables tab of a contract that is in Draft or Under Amendment status. Once the contract becomes active and deliverables are automatically activated creating deliverable instances, you can only make changes to deliverables status, notes and attachments using the Manage Deliverables task. For internal deliverables with a fixed due date that you can manually activate at any time irrespective of contract status, you can only make changes to deliverable definition details before you activate them.
References:https://docs.oracle.com/cd/E56614_01/procurementop_gs/FASCA/F1174613AN14980.htm

Explanation
https://docs.oracle.com/en/cloud/saas/procurement/20a/oaprc/manage-supplier-information.html#OAPRC122404 Default Assessment Owner: Select a user to set as the default assessment owner for all the accessing procurement BUs when this qualification model is included in an assessment. When a default assessment owner is assigned, then all theprocurement BUs that have access to this model will have this user as the default assessment owner unless specified otherwise in the Business Unit Access or Business Unit Defaults table.
Business Unit Access: You can assign a default assessment owner for various business units. When the area isn't global BU access, you can also add the procurement business units which can use this qualification model.