The Open Group Architecture Framework
The Open Group Architecture Framework (TOGAF) provides a comprehensive approach to the design, planning, implementation, and governance of an enterprise information architecture. The architecture is typically modeled at four levels or domains; Business, Application, Data, Technology. A set of foundation architectures are provided to enable the architecture team to envision the current and future state of the architecture.
TOGAF also provides a highly detailed Architecture Development Method (ADM) that is tailored to the organization's needs and is then employed to manage the execution of architecture planning activities.
A reference section provides numerous useful tools and guides that can be helpful in the architecture development process.
The Open Group provides TOGAF free of charge to organizations for their own internal noncommercial purposes.