Approval process triggered when Discount of Sales Order is updated

Hi, Everyone;

Does somebody have the answer for my question in SAP Business ByDesign?

My requirement as below:

In the sales order view, we have setup the default discount for product-ABC, the default discount is -55% (which was maintained under Product and Service Portfolio --》Pricing --》Discount Lists), but in some cases, we need to update this default discount manually in sales order view .

I would like check with you , when we update the default with other values, can system trigger the approval process automatically?  if yes, how to setup?