in the sample models that ship with Vensim, navigate to the \Models\Sample\Sub-Model\ folder. In this folder, there are three separate models, market_model.mdl, products.mdl and advertising.mdl. These are derived from the market model that also ships with Vensim (\Models\Sample\MARKET).
"products.mdl" calculates everything relating to the "product" view from the market model. There is one parameter that would have been calculated by the market model ("prod dev budget"), this is a constant in this model to allow it to simulate independently from the market model.
"advertising.mdl" calculates everything relating to the "advertising" view from the market model. "adv budget" and "products" are parameters that would have been calculated by the market model. In the advertising model, these are constants to allow it to simulate independently from the market model.
"market_model.mdl" is the parent model. If you open this, it will in turn open the two sub-models. You can view the sketches from the sub-models using the view selection on the bottom toolbar. You can simulate the model and use all the existing Vensim tools (such as causal tracing, graphs and tables).
"market_model_original.mdl" is the original model that was split into the market model and it's two sub-models.
