Approval Rule on Change Assignment for FTE and Headcount Changes

Hello,

I'm configuring an approval rule through Approval Rules (Transaction Console) for the Change Assignment transaction.

My requirement is to send an Information Only notification whenever either the FTE or Headcount value is changed.

However, when configuring the rule and selecting attributes from Worker's Current Assignment and Worker's Proposed Assignment, I can't find either FTE or Headcount among the available attributes.

Has anyone implemented a similar approval/information-only notification for FTE or Headcount changes?

Any examples or best practices would be greatly appreciated.

Thanks!

Rebecca