1. A method for predicting performance of an application on a machine of a predetermined hardware configuration, the method comprising: simulating, in a computer process, the performance of the application under a plurality of different simulated hardware configurations; building, in a computer process, a predictive model of the performance of the application based on the results of the simulations; obtaining the performance of the application on a plurality of actual machines, each of the machines having a different hardware configuration; and in a computer process, Bayesian reinterpreting the predictive model built from the results of the simulations using the performance of the application on the plurality of actual machines, to obtain a final predictive model of the performance of the application having an accuracy greater than the predictive model built from the results of the simulations.