Abstract: A system is disclosed which functions in two distinct yet interrelated modes. In a modeling mode the system provides a customized multi-body model, wherein problem specific functions are created for analysis of complex real-world machines. A preprocessor facilitates the multi-body model description and a symbolic generator then generates model specific code in FORTRAN of some other convenient computer language. The model code is portable and self contained. In a numerical simulation mode actual multi-body system data are combined with the model code, whereby the system is manageable by a user not necessarily familiar with the modeling techniques, but familiar with the multi-body system modeled. Simulation operations by the system produce outputs descriptive of the multi-body system without redundancy, which outputs may then be utilized by the user through a post processor to compute further quantities of interest and to apply visualization to interpret results.