Using a submodel to show the main components of a complex model

You have constructed a model with a number of compartments and flows. Some relate to vegetation; some to the animals in the area; some to soil water and nutrients. By grouping the model-diagram elements for these different parts into submodels (called “Vegetation”, “Animals” and “Soil”), the gross structure of the model is immediately apparent.

Conversely, you may prefer to design a model in a top-down fashion. Starting with a blank screen, you can rapidly add submodels corresponding to the main components of a proposed model, then subsequently add the various compartments, flows etc inside these.