The technique of "semi-analytic modeling" or, perhaps, "phenomenological galaxy formation modeling" takes the approach of treating the various physical processes associated with galaxy formation using approximate, analytic techniques.

What is semi analytic?

The word “semi-analytical” is used because the DTFM delivers exact closed-form analytical solutions at least in one coordinate direction. The thrust of the method is that it is capable of modeling multi-body regions like the FEM and at the same time maintains high accuracy and efficiency of analytical solutions.

What is meant by analytical model?

An analytical model is quantitative in nature, and used to answer a specific question or make a specific design decision. Different analytical models are used to address different aspects of the system, such as its performance, reliability, or mass properties.