The information below is about how to prevent the users from removing the current Provisioning Roles already assigned to them but still allow the users to assign new Provisioning Roles.
Identity Manager 14.x
Open the Identity Manager UI
1. Modify the Admin Task the user will use to assign Provisioning Roles (i.e Modify User)
2. Select the Tabs tab
3. Edit the "Provisioning Roles"
4. From the new page, check the options below
5. Click OK and Submit buttons
6. Selecting the custom Modify User Task, the Provisioning Role tab will display like this