Various groups and framework have developed approaches and knowledge regarding Business Architecture as pointed out by Wikipedia. They include the following:
The Object Management Group

The BAWG conducts periodic Business Architecture Information Days at the OMG's quarterly Technical Meeting as part of an outreach effort to bring interested practitioner and vendor organizations into the standards process.
The BAWG Modeling Workgroup is currently working to develop a standard framework for business architecture that is aligned with the Business Architecture Guild Business Architecture Body of Knowledge Handbook.
The Zachman Framework
The Open Group

The TOGAF framework includes “Business Architecture” as one of the four "domains" of architecture. The other 3 domains are Application Architecture, Data Architecture and Technology Architecture. TOGAF describes business architecture as follows: "Business Architecture describes the product and/or service strategy, and the organizational, functional, process, information, and geographic aspects of the business environment."
TOGAF describes a nine-step process in the Business Architecture phase as followed:
- Select Reference Models, Viewpoints, and Tools
- Develop Baseline Business Architecture Description
- Develop Target Business Architecture Description
- Perform Gap Analysis
- Define Candidate Roadmap Components
- Resolve Impacts Across the Architecture Landscape
- Conduct Formal Stakeholder Review
- Finalize the Business Architecture
- Create Architecture Definition Document