This paper presents how a scientific application written using an SPMD programming model with message-passing can be modeled and simulated. This description is based on the counting of basic operations and the recognition of known kernels. A Fortran analyzer was built to generate automatically a model of such an application for the simulation tool of the MIMESIS project, developed at EDF (Electricite de France). Models of distributed-memory computers, taking advantage of this description, were implemented with the prototype of the project. The approach was validated with two EDF codes, for which the simulations gave good results.