Sales Agreement work flow

Hi All,
As per the standard Sales Agreement work flow, status of the agreement changed to "Active" once it is approved based on the Approval hierarchy.

But when there is an Item Price change, then Sales Agreement needs to be submitted for Approval again as per the business requirement.

Is there any way to activate the standard work flow? so that Sales Agreement status changed to 'pending for Internal Approval" till it is finally approved.

If anybody worked on similar requirement, Please kindly share your solutions / ideas.

Thanks in Advance.

regards,
Ramakrishna.