This paper describes a method for the “Analysis and Prediction of the Performance of Evolving Architectures” (APPEAR). This method aims at performance estimation of the newly developed parts of software product families during the architecting phase. The method combines both structural and statistical techniques in a flexible way, i.e. it allows one to choose which part of the application is structurally described, modeled and simulated, and which one is statistically evaluated. The method is being validated with case studies in the Consumer Electronics domain and the Medical Imaging Systems domain. The results of the initial validation of the statistical part of the method, described in this paper, are encouraging.