EPCM Model View - Role Usage

Summary:

In EPCM there is a role for Model - View. What is the usage of this role and where should we use this?

Content (please ensure you mask any confidential information):

In EPCM there is a role for Model - View. If we provision personnel as User and assign this role expecting the Models will have only View access it does not happen like that, and they get edit access to the model as application provision role of USER seems to be taking the precedence. If we provision personnel as a viewer, this role need not be applied at all because that personnel get only View access by default. So, what is the real usage of this role?