V7.1: make Business Role available in IT-Shop. (Assignment Ressource could be ordered more than once)

Question

After the migration from 6 to 7 our requestable Business Roles has an Assignment Ressource. 
 The problem is, that an assignment ressource could be requested more than once, but IMHO that doesn't make sense in case of a business role. 
 
 Could anyone give me a brief description how business roles should be made requestable, that it's not possible to order them twice? 
 
 Patrick

Markus Weiss-Ehlers · Accepted Answer

Just think about the fact that you can restrict the duration of your request. 
 
That means that you are able to request the same membership for different time periods. This is a heavy used features by several customers, especially with larger, distributed organizations. 
 
And as Geraldine tried to point out, to check and remove all products during the search in the product catalog leads to longer UI response times, especially when your catalog contains thousands of items. 
 
That, and some additional, are the reasons why the product behaves as is. 
 
Feel free to modify the behavior to the restricted needs of your customer.