The Seven Types of Enterprise Architecture

For about 40 years, I have been paid to lay out the structure (architecture) of systems. I get paid to do architectures. Here are the types I have been paid for. The list is much more useful than that simple description posits.

The Seven Types

Here are the 7 types as I understand them:

1. Executive or Enterprise Architecture: This type aligns with the "Enterprise Integrating" activity, focusing on portfolio-level optimization. It addresses the enterprise as a sociocultural and techno-economic system, optimizing shared assets—strategies, processes, data, and technologies—to align with mission and goals (citing Burk, OMB 2006). Senior leaders rely on this architecture to ensure strategic coherence, a principle I emphasize as critical to effective EA.
2. Segment or Mission: Architecture Corresponding to the "Enterprise Ecological Adaptation" activity, this type supports program or functional management. It develops roadmaps for core mission areas or business services (e.g., human resources, product lines), fostering innovation and adaptation to the enterprise’s environment (citing Lapalme, 2012). This reflects my view of EA as a tool for organizational learning and responsiveness.
3. Solution or System Architecture: Linked to the "Enterprise IT Architecting" activity, this type focuses on project-level design of IT assets (applications, components) to automate business functions. It ensures alignment between IT capabilities and business strategies, a practical application I advocate to maintain competitive advantage (citing Lapalme, 2012).
4. Reference Architecture: This servs as a standardized blueprint or pattern for other architectures. It provides reusable frameworks and best practices, supporting my governance principle of structure and reuse (citing Burk, OMB 2006). Reference architectures enable consistency across projects, aligning with my call for clarity in EA practice.
5. Domain Architecture: Domain Architecture focuses on specific business or technical domains (e.g., finance, infrastructure) or functions. It optimizes these areas within the enterprise context, reflecting my emphasis on aligning diverse facets to minimize contradictions (citing Lapalme, 2012), and supports the Governance activity by ensuring domain-specific coherence.
6. Spot or Point Architecture: This type addresses narrow, tactical needs within a single project or system, akin to a focused subset of Solution Architecture. It embodies my pragmatic approach by enabling quick, targeted interventions, a concept that complements the Maturity Management activity’s focus on iterative improvement based on real data (citing Hite, GAO 2010).
7. Meta Architecture: The overarching type, Meta Architecture, provides a high-level framework that governs and integrates the other six. It aligns with the Governance and Maturity Management activities, offering a reflective lens to assess and improve EA processes across the enterprise (citing Hite, GAO 2010). This type underscores my vision of EA as a self-improving discipline, rooted in its original IT management intent (NIST 1989).

Relation to Frameworks

These types are not new.

The Enterprise, Segment and Solution types were defined in FEAF and are echoed in TOGAF. The Reference Architecture is widespread in DoDAF, where Segment Architectures become Mission Architectures. DoDAF still retains the Solution Architecture.

A Framework is a Meta-Architecture or the stat of one, before it is tailored to customer needs and the practice becomes more mature (cf. OMB EAMMF). The point architecture describes a common practice within the Zachman framework of using architecture to solve varied problems.

The Domain Architecture is not uniformly defined. A Domain is similar to a TOGAF Partition. Some think a Domain corresponds to the Enterprise Architecture subdomains that define holism, Business, Data, Application, Infrastructure... (AI thought domain referred to the FEAF reference architectures.) I simply say it is not a segment, some function.

What I do with this list is simply to give a consolidated list that is less confusing.

Some Notes

• The "Ecological Adaption" verbiage to me seems impractical. I define a segment as a Line of Business, either a Product Line or a Service Line. A Segment Architecture then simply becomes the documented holistic structure of one of those.
• I call it an "Executive Architecture" because at one time Burk said roughly that "Enterprise Architecture consists of three levels, 1) Enterprise Architecture..." which was a semantic mess and very confusing. Several early architects used the "Executive Architecture" term to avoid long confusing discussions.
• An architecture in Enterprise Architecture is a collection of artifacts, lists, matrices, drawings, or documents.
• All types have holism, and cross business, data, application, infrastructure, interface, etc., as needed, describing all of these. This principle drives the avoidance of defining a Domain Architecture as a single one.
• In the beginning, Enterprise Architects sought to build one big, comprehensive architecture. That approach did not work. As a result, Enterprise Architecture became a nested set of different types.

An Argument of Architects

It is said that there is a flock of sheep, a murder of crows, and an argument of architects. We argue and disagree about everything, seeking the truth. I urge you to simply adopt this nomenclature and argue about useful things instead.

References

• Burk, S. (2006). Federal Enterprise Architecture Framework (FEAF). Office of Management and Budget (OMB). https://www.omb.gov
• Fong, E. N., & Goldfine, A. H. (1989). Information management: The integration challenge. National Institute of Standards and Technology (NIST). https://nvlpubs.nist.gov
• Hite, R. (2010). Enterprise architecture management maturity framework (EAMMF). U.S. Government Accountability Office (GAO). https://www.gao.gov
• Kern, M. (2014). EA as 5 activities. http://mkern.com/__static/d79d10d5f0c6cb28f116da64e93f76c0/ea_as_-5-_activities_2014(2).pdf
• Kern, M. (n.d.). The original meaning of enterprise architecture. http://mkern.com/__static/dbceb2408319b8b5b6aaddcd5ed13676/the_original_meaning_of_enterprise_architecture.pdf
• Kern, M. (n.d.). The seven types of enterprise architecture [PowerPoint slides]. http://mkern.com (inferred URL based on context).
• Lapalme, J. (2012). Three schools of thought on enterprise architecture. IT Professional, 14(6), 37-43. https://doi.org/10.1109/MITP.2012.89
• Project Management Institute (PMI). (2013). A guide to the project management body of knowledge (PMBOK guide) (5th ed.). PMI.
• Spewak, S. H., & Hill, S. C. (1992). Enterprise architecture planning: Developing a blueprint for data, applications, and technology. Wiley.
• U.S. Congress. (1996). Clinger-Cohen Act of 1996. Public Law 104-106. https://www.congress.gov
• Zachman, J. A. (1987). A framework for information systems architecture. IBM Systems Journal, 26(3), 276-292. https://doi.org/10.1147/sj.263.0276
• Zachman, J. A. (1993). Enterprise architecture: The Zachman framework. Zachman International.
• Office of Management and Budget (OMB). (1996). Circular A-130: Management of federal information resources. https://www.omb.gov
• Department of Defense (DoD). (n.d.). Joint Capabilities Integration Development System (JCIDS). https://www.jcs.mil
• Department of Homeland Security (DHS). (n.d.). Enterprise architecture governance. https://www.dhs.gov
• GAO. (2012). Organizational transformation: A framework for assessing and improving enterprise architecture management (Version 2.0). U.S. Government Accountability Office. https://www.gao.gov
• Bernard, S. A. (2012). An introduction to enterprise architecture (3rd ed.). AuthorHouse.
• The Open Group. (2011). TOGAF version 9.1. https://www.opengroup.org
• Ross, J. W., Weill, P., & Robertson, D. C. (2006). Enterprise architecture as strategy: Creating a foundation for business execution. Harvard Business Review Press.
• Schekkerman, J. (2008). Enterprise architecture good practices guide: How to manage the enterprise architecture practice. Trafford Publishing.
• Lankhorst, M. (2013). Enterprise architecture at work: Modelling, communication and analysis (3rd ed.). Springer.
• Simon, D., Fischbach, K., & Schoder, D. (2014). Enterprise architecture management and its role in corporate strategic management. Information Systems and e-Business Management, 12(1), 5-42. https://doi.org/10.1007/s10257-013-0213-0
• Winter, R., & Fischer, R. (2007). Essential layers, artifacts, and dependencies of enterprise architecture. Journal of Enterprise Architecture, 3(2), 1-12.
• U.S. General Services Administration (GSA). (2013). Federal enterprise architecture framework (FEAF) reference models. https://www.gsa.gov
• TOGAF. (2020). The TOGAF standard, version 9.2. The Open Group. https://www.opengroup.org/togaf