A method for a discrete event simulation model of a system utilizing a just-in-time compilation for one or more code blocks associated with an event in one or more discrete event simulation models is disclosed. The method comprises the steps of determining the event in a discrete event simulation model, retrieving the code block associated with the event, compiling the code block into an object file using a compiler, linking the object file with a predetermined function in a simulation library, compiling the object file and the predetermined function into a customized dynamic link library, loading the customized dynamic link library (DLL) within a discrete event simulation program execution and linking the customized DLL to a simulation program. The method allows user entered logic to be executed in high speed by integrating a just-in-time compiler embedded into the discrete event simulation model to allow dynamic generation of high speed code blocks within one or more simulations.