When is the abo_delta_ext BML function is triggered?

Summary:

When are the ABO functions triggered?

Content (required):

After reading the 19B_ABO_Implementation_Guide_October2021.pdf we enabled the ABO in our environment. We defined the _ORCL_ABO.abo_delta BML function in the BOM Declaration section.

We modified the "abo_delta_ext" function with a print statement (just to check if is getting triggered), but we didn't get any result in the log after we clicked on the "Save" button in the Configuration page.

When are the "abo_delta" and "abo_delta_ext" functions getting triggered? Each time the "Save" button in the Configuration page is clicked, or there is a check if in the Configuration we are modifying a CPQ Asset?