Anyone who works for a "staff function" or a "support function" will tell you that the nature of this function is advisory. The people belonging to this function investigate, research, and give advice to their line managers. The value of the function really then lies in becoming a trusted advisor to the business. Being a trusted advisor simply means that the "clients" value the deep subject matter expertise that the specialist brings to the table. All advisory professions have to earn the trust of the client without which they are not relevant. That is as true for Human Resources professionals as it is for a doctor, a lawyer, an accountant ... the list goes on. The feeling of professional self worth of such professionals is very directly linked to how valuable they and their advise is to the others. The more they are consulted the more valued they feel.