How to extend InventSum Table update or insert method

Hello AX Masters,

I have a request to create a log on every time there is a change in InventSum table. So, I’ve modified ‘update’ and 'insert' methods on InventSum table and added my code to insert record into log table.

On PO, when I create a Product Receipt and post it, code doesn’t touch update method. However I do see ‘Received’ qty has been changed in InventSum table.

Please advise.

Thank you in advance.

Ragin