Heterogeneous hierarchical models

Complex systems are not amenable to the use of a single model or level of abstraction in describing their dynamic system characteristics. It is often necessary to tie several models together if we want to reason, simulate, or analyze the system. Moreover, the use of a hierarchical representation helps us to more intelligently organize the models. We discuss a modeling process called heterogeneous hierarchical modeling (HHM) which supports multiple representations and supports hierarchical development of time dependent knowledge. Additionally, a hierarchical heterogeneous model provides a natural structure for knowledge- based reasoning. A knowledge-based environment requires such models in order to suggest improvements, guide semantic development, or analyze autonomous decision making models.