Suppose we want to model more accurately the production capacity sector of a firm. If, somewhere, we have an existing model that describes the capacity sector better than our current model, we can use this model to enhance and refine our current model. We have a model called cap1.mdl that builds capacity based on investment with a construction delay, and that depreciates capacity only after the capacity life is used up. This implies that we cannot reduce capacity any faster than it depreciates (unlike our other model where capacity could be reduced at the same Rate as it was built). This section introduces the concept of merging two different models (structure and equations) to form one complete working model.
