Q: What is the Model Driven Architecture (MDA) and how is it different from other architectures?
A: The MDA is a new way of writing specifications and developing applications, based on a platform-independent model (PIM). A complete MDA specification consists of a definitive platform-independent base UML model, plus one or more platform-specific models (PSM) and interface definition sets, each describing how the base model is implemented on a different middleware platform. A complete MDA application consists of a definitive PIM, plus one or more PSMs and complete implementations, one on each platform that the application developer decides to support.
MDA development focuses first on the functionality and behavior of a distributed application or system, undistorted by idiosyncrasies of the technology or technologies in which it will be implemented. MDA divorces implementation details from business functions. Thus, it is not necessary to repeat the process of modeling an application or system's functionality and behavior each time a new technology (e.g., XML/SOAP) comes along. Other architectures are generally tied to a particular technology. With MDA, functionality and behavior are modeled once and only once. Mapping from a PIM through a PSM to the supported MDA platforms will be implemented by tools, easing the task of supporting new or different technologies.