When making changes to an already existing AML InternalElement, two strategies can be followed:

• Change the InternalElement directly. Here, every operation (add, change, delete) is possible as long as it does not violate a rule from the OPC UA standard. However, in these cases, the original instance is not kept.
• Convert the InternalElement to an SUC, make the SUC a subclass of the SUC from which the InternalElement was created, and make an instance from this new SUC for further editing. This allows the original InternalElement to be kept as an SUC in the type system. If this is done repeatedly, an instantiation step is followed by an SUC-conversion step, and the work history is available in the derivation chain of the modelled SUCs.