A system to performance tune a site system , comprising: one or more controllers , each of the one or more controllers being configured to control a respective one of one or more subsystems of the site system by changing values of a respective set of parameters ; a site reference model configured to indicate a target performance of the site system, the target performance indicating an ideal performance of the site system according to a design of the site system; a processor configured to instruct the one or more controllers based on the target performance for the site system defined by the site reference model a site specific model configured to indicate an actual output of the site system , wherein the processor determines a difference between the site reference model and the site specific model to determine a performance gap of the site system; and a memory device configured to store a priority and a tolerance associated with each parameter of the set of parameters for each of the one or more subsystems of the site system, the priority of a parameter indicating an order in which to change the parameter and the tolerance of the parameter indicating an amount within which to change the parameter, wherein the processor sets a target subsystem performance for each of the one or more subsystems and instructs the one or more controllers to control the respective one or more subsystems based on the performance gap and the target subsystem performance according to an analysis of the performance gap of the site system; the priority of parameters of the one or more subsystems; and the tolerance of parameters of the one or more subsystems. one or more controllers , each of the one or more controllers being configured to control a respective one of one or more subsystems of the site system by changing values of a respective set of parameters ; a site reference model configured to indicate a target performance of the site system, the target performance indicating an ideal performance of the site system according to a design of the site system; a processor configured to instruct the one or more controllers based on the target performance for the site system defined by the site reference model a site specific model configured to indicate an actual output of the site system , wherein the processor determines a difference between the site reference model and the site specific model to determine a performance gap of the site system; and a memory device configured to store a priority and a tolerance associated with each parameter of the set of parameters for each of the one or more subsystems of the site system, the priority of a parameter indicating an order in which to change the parameter and the tolerance of the parameter indicating an amount within which to change the parameter, wherein the processor sets a target subsystem performance for each of the one or more subsystems and instructs the one or more controllers to control the respective one or more subsystems based on the performance gap and the target subsystem performance according to an analysis of the performance gap of the site system; the priority of parameters of the one or more subsystems; and the tolerance of parameters of the one or more subsystems. <EOS>