Hansov,
You're creating a parameter by defining a relation, so you'd need to add the relation to all the models. The adding of relations to all the models in your WS can be mapkey'd/scripted as well as adding the BOM_DESCRIPTION to the family table and verifying the table. If you're using mapkeys and OS scripts, error trapping is sometimes difficult if not impossible for when something goes wrong. You may also be able to add the relation via ModelCHECK run in update mode. We don't use ModelCHECK to check our relations, so I don't know if this will work or not. Assuming it would work, once ModelCHECK is setup, you can run ModelCHECK in batch mode for all the objects in a folder. This is good if all the relations are identical.
I would skip step 5 until all models are updated and you've checked that all instances verify successfully.
If you just need to add & set the value of a parameter (that is not driven by a relation) for multiple models, you can do this in the workspace via EDIT > ATTRIBUTES. The table display will need to have a column for the parameter you're adding and setting. If the model does not already have the parameter defined, it will be created (except for family table instances). You need to enter each value individually, but at least you don't need to open every model individually. For family table instances, the parameter must already exist in the model and be part of the family table in order for you to modify the value.
Regards,
Dan N.
