1. A method for automatically converting with a data processing apparatus a simulation program written by a function description language into an executable program written by a selected programming language, comprising the steps of: creating a simulation program written by a function description language and including sequential and parallel process variables; discriminating the parallel process variables from the sequential process variables in said simulation program; converting the parallel process variables into corresponding sequential process variables, thereby converting said simulation program into an intermediate program free of the parallel process variables; and converting said intermediate program into an executable program written by the selected programming language and using a predetermined scheduler which controls a sequence of occurrence of events as a function of simulation time.