Can the meta data in the Asset Hierarchy have two SAP ID numbers?

You can always add extra / new properties to the existing views.

But changing the behavior of existing properties is not possible without creating a new version. 

In general: 

A breaking change in data modeling occurs when modifications to a data model prevent existing queries or functionalities from working as intended. For example, if you copy a type definition without using the @import directive, it creates a new view independent of the core data model, making it impossible to access data from the core model. This can disrupt functionalities like path materialization.

Please see: https://docs.cognite.com/cdf/dm/dm_guides/dm_extending_core_data_model

Thanks Jan for your answer,

So to state it better and give an example

This is how it was:

and this is now how it looks like:

For all important equipment it has now a new equipment number and on the technical ID number and the description only some text was added after the important number.

If the new equipment number is added to the metadata of the current equipment hierarchy in CDF as a 2nd SAP ID number would that work? Or should we substitute the SAP ID numbers for the new numbers and create a new field keep the old numbers in a say Legacy sap ID meta data field?

what would best way to proceed, also to test if we can find then under the same TechID number both sap notifications made for old and new equipment numbers. For the maintenance engineers using SAP this is painful to find the good history of the data.

Thanks Ramon