If an engineer visits a site for the second time on the same call number, a purchase order will not generate automatically. Purchase orders are triggered when a call is despatched to the engineer. To generate one for a repeat visit, try one of these options:
Undespatch and redespatch the call to the engineer.
Have the engineer close the call and ask the service desk to raise a new call and despatch it to the engineer.
You can also mark the call as Another Visit Required when closing it, then select the **Assign and Dispatch to me** checkbox.