Customization of existing modules

Hello everyone, I am personalizing the HR modules for Colombia in which I am adding some calculations to extract from the base salary of an employee a percentage that the company must pay.

What is the best way to make these personalizations? for when there is an update of the ERPNext they will not be deleted and must do everything again?

Should I do them in a separate module and / or how do I apply inheritances so that what I do I take if there is any update of the ERP?

Thank you so much!

Create a custom module and in the doctype link your formulas when erpnext updates does not update the database and since it is a customized module it will not have it in

Hi @Rodolfo_Pablo_Silva,

if it is only additional calculations, I would look into adding custom fields (DocType you want to extend > customize) and put your customisation into a custom script. Therefore, your source remains on the regular branch but you can add functionality. More on custom script on Developer Cheatsheet · frappe/frappe Wiki · GitHub

Hope this helps…