Inside the Roles Tab, define the Assignor, Assignee and Associate roles and sometimes Auditor according to the use cases,.
Rationale: In ERP5, all documents should follow the 5A Security model in which
users are associated with roles in a per-module and/or per-document basis. Most
of the times, the user who can create a document will have an "Assignor" role
and the user who have to validate that document will have an "Assignee" role.
Once all the roles are correctly defined on the portal type, you should do an
"Update roles settings" so that all existing documents get the correct local roles.