The service level philosophy in our call center is simple. You can’t just keep adding staff to solve customer contact issues/problems. I think you ‘ve got to look at more effective solutions, by combining the skills ,technology and operational efficiencies to mangage a complex inbound service. In our skills-based routing environment, we have specialized groups, so we run interactive calculations. The Erlang-C method remains an accurate tool and it will probably always be around for teaching people queuing dynamics.