1. A method for deriving an analytic model for a session-based system, the method comprising: receiving, by a model generator, client-access behavior information for the session-based system, wherein the session-based system supports a plurality of interdependent transaction types, and wherein said client-access behavior information comprises transition probabilities of the plurality of interdependent transaction types; and deriving, by the model generator, from the transition probabilities of the plurality of interdependent transaction types, a stateless transaction-based analytic model of the session-based system, wherein the derived transaction-based analytic model models resource requirements of the session-based system for servicing a workload, wherein said deriving further comprises determining, from the transition probabilities, a vector π i that represents a steady-state probability for the plurality of interdependent transaction types, and wherein the determined vector, π i , gives the overall percentage of the interdependent transactions of type i in the workload of the session-based system.