Continuous model simulation systems have evolved in the present decade from the monolitic CSSL 1967 architecture to new and more powerful modular ones. However, in spite of this constant evolution, the majority of the continuous model simulation systems available in the market have an architecture based on the 1967 standard. Furthermore, the programming language in which the majority of theses systems are developed is still Fortran. In spite of the engineering value, the use of Fortran or other classical procedural languages has constrained the degreee of moduarity, felicibility and reliability of the simulation systems. Therefore, the adoptin of new protramming methodologies is advisable. At present, it seems that de object-oriented approach is one of the most promising.