How to Change a Custom Field to a Roll-up/Formula Field

Question

I have a custom field on the Account object that had been getting populated by an external data source. We are making changes and will no longer be populating the field from the data source but are instead able to make a Roll-Up Summary field with the same value.

I was hoping to simply edit the existing field and change it to be the Roll-Up Summary field, but that does not appear to be possible.

My next thought is to delete the existing custom field and then create the new Roll-Up Summary field with the same name.

Is that the easiest way to accomplish this?

Answer 1

It's "easy" if you have no dependencies, but you may need to end up backing up reports, dashboards, code, page layouts, compact layouts, list views, field level security, etc, before deleting the original field, as you may need to restore any affected configurations later. Deleting a field almost always has deep implications.