Method and systems for managing QoS models for traffic flows in a network are described. In particular, the method includes storing the QoS models and analyzing at least one of the QoS models to determine whether the QoS model satisfies a suitability test. One or more QoS models are then selected based on the analysis and these selected models are offered to a client for use with a traffic flow in the network. In one embodiment, the method may be implemented based on a query from a client requesting reservation of network resources for a traffic flow. The analysis may be based on a characteristic of the or each QoS model, of the client, of a query received from the client requesting reservation of network resources for the traffic flow or of the network or an operator of the network.