Several approaches exist for the numerical representation of optical fields. These approaches differ with respect to the amount of information from the original field which is represented. Based on these numerical field representations, a number of different propagation methods are known which have different properties concerning physical accuracy and computational effort. Well-known examples are the ray tracing approach and Fourier transform based wave optical propagation methods. A modern optical engineering software should therefore enable the usage of different field representations and propagations methods within the modeling of an optical system. The spread sheet approach for modeling an optical system, which is used for instance in ZEMAX, can be extended for allowing a more flexible assignment of different propagation methods to certain parts of the optical system. This generalized approach, which is implemented in VOL4 VirtualLab, is demonstrated by practical example from laser beam shaping. Furthermore, an overview is given to the wave optical design approach implemented in VOL4 VirtualLab.