This paper describes how we can use four modelling methods together. We model Information and Communication Technology (ICT) systems and Business Process (BP) systems. The aim of the modelling is to experiment with the models, that is, simulation. Two of the methods are the detailed modelling of the ICT and of the BP systems, as we usually do that for discrete event simulation. The other two methods are those that enable us to make rapid performance analysis of these systems, namely Traffic-Flow Analysis (TEA) for ICT systems and Entity Flow-phase Analysis (EFA) for BP systems. The solutions for the combination and interworking of these methods are described.