Expensive CAD API calls for ship hydrostatics property evaluation

“How to structure dependent, cached property evaluation without coupling data and logic? I am building a desktop application that performs ship stability and hydrostatics simulations by using a 3D model designed by the user in a CAD program, using that program's API. When simulation is complete, my application needs to perform various measurements (evaluations), based on what user requested before starting the simulation. For example, user might require measurements like waterline length, width, ”