A company creates blanket purchase orders from inbound documents that are sent to Dynamics 365...

In Dynamics 365 Business Central, workflows are the tool used to control document approvals, including purchase orders:

Lock the record for newly created blanket purchase orders with the specific item → Business Central workflows

Blanket purchase orders are controlled via approval workflows in Business Central.

Workflows enforce rules so records cannot be processed until approved.

Assign the security command that tells the system to lock the purchase order → Then Response

In workflow design:

When Event defines the triggering action.

On Condition specifies filter conditions.

Then Response is the action taken, e.g., Lock the record or Request Approval.

Therefore, locking the record is a response action.

Assign the items that the system will want to use to trigger the locking of the purchase order → When Event

The workflow must know what starts the approval process (such as A blanket purchase order is created).

This is always defined as a When Event.

Other options not correct:

Incoming Documents / Power Automate flows → Can be integrated, but the requirement here is internal approval and locking, which is a Business Central Workflow function.

On Condition → Used to apply filters (like a specific item), but the actual trigger is defined by When Event.

Trigger → Not a component in Business Central workflow terminology (more of a technical developer concept).

Microsoft Learn References

Set Up Approval Workflows

Workflows in Business Central