How to identify organization-specific service roles

Hello,

We have 4-5 types of employees assigned to each organization, such as sales, service, finance. RightNow allows the specification of the sales rep out of the box, but how can we specify the other types of employees assigned to the organization so that the employees are available via picklist?

Today we maintain a custom field on the Organization object which requires manual updating when employees arrive or depart. How can we map the picklist to the particular profile associated with the role?

Thanks,

Patrick