How to understand BOM creation in Microsoft Dynamics 365 for Operations (AX7)

The way you create BOMs in Microsoft Dynamic 365 for Operations (aka AX7) has slightly changed from earlier versions and can throw even an experienced user for a loop.

Let's start with AX 2012 and make sure we completely understand how it worked there. Normally we create BOMs from the Released Product.  I am on a released product and after clicking "lines" in the Engineering section of the action bar in the top, we get this screen, the very familiar BOM-screen.

We could always choose between "New" and "Create BOM".  Remember how you clicked "New" and regretted it?

If you are like me, you by far preferred "Create BOM" because it creates a BOM version in the background (when you have the number sequence set up to generate numbers automatically) and you only have to enter BOM version description and indicate a site. This is much quicker than the "New" choice. But let's take a minute to fully understand how that "New" works.

What happened when you click "New"? You saw this screen.

The system is obviously waiting for a BOM-id. Many of us typed in some BOM-id. But that never worked. You can't type it in. You have to do ‘Right click - View details" to go to the table where you create a new BOM-id. You would end up with the following: