Mechanisms are provided for controlling a fidelity of a simulation of a system. A model of the system is received, the model of the system having a plurality of individual components of the system. Fidelity values are assigned to models of the individual components of the system. A required fidelity value is assigned to transactions between components in the plurality of individual components of the system. A simulation of the system is executed using the model of the system and the models of the individual components of the system. The fidelity values of one or more of the models of the individual components of the system are dynamically adjusted during the execution of the simulation based on the required fidelity values assigned to the transactions.