To retrieve the Artikel objects that are below a certain threshold you could create an Xpath for that. Is a bit faster then iterating over your list. We can help you with the XPath if you give some details on which attributes you want to check. You then have to check if the parameter Artikel is part of that list. You have list operations for that: https://docs.mendix.com/refguide/list-operation
Use the contain function to see if Artikel is part of the ArtikelList. If true you can do the stuff you want to do.
Regards,
Ronald