A segment is just a sub-division or subset of the full enterprise
Have you ever come across anyone with the title – “Segment Architect”? No? Well neither have I. And yet the role is one that crops up in several parts of the TOGAF® documentation. So what is this missing role of the segment architect?
I’ll start by listing the places in TOGAF where you will find mention of this elusive role:
- In the Architecture Skills Framework (Chapter 52) TOGAF describes three categories of architect – Enterprise Architect, Solution Architect, and Segment Architect.
- In Applying the ADM across the Architecture Landscape (Chapter 20) and the Architecture Repository (Chapter 41), TOGAF divides the architecture landscape into three levels of granularity or types of organizing framework:
- Strategic Architectures, which show a long-term summary view of the entire enterprise, supporting operational and change activity and allowing direction setting at an executive level.
- Segment Architecture, which provides more detailed operating models for areas within an enterprise, supporting operations and change, through direction setting and architecture roadmaps at a program or portfolio level.
- Capability Architectures, which show in more detail how the enterprise can support a particular capability by developing architecture roadmaps to realize capability increments.
[Note: the idea of partitioning the architecture according to these three levels is discussed further in Architecture Partitioning (Chapter 40)]
- This idea of partitioning the architecture into three levels of granularity is also discussed in the Introduction to the ADM (Chapter 5). In this chapter TOGAF talks about how architecture artifacts need to be integrated across these levels.
The key point here is that segment architecture is simply “a detailed, formal description of areas within an enterprise, used at the program or portfolio level to organize and align change activity” (link).
In other words, a segment is just a sub-division or subset of the full enterprise. Any sub-division or subset, however you choose to make that subdivision.
Some organizations have segments that correspond to the organization structure. For example, within a large international bank there might be a Retail Bank Segment and a Corporate Bank Segment. But the architect responsible for these areas would probably be called “Retail Bank Architect”, or possibly be given a more generic title like “Business Unit Architect”.
Other organizations have architects responsible for particular sub-domains. For example, there might be an architect responsible for Payments, Customer Relationship Management, or Fraud. The job title for these architects might include the domain name, such as Product Architect, or it might reflect a functional area within a business, such as Sales and Support Architect. TOGAF describes four high-level domains – business, data, application and technology – and these are often used in the job titles for architects focusing on those subjects.
TOGAF is not actually describing a particular role, but more of a type of architecture role. If we go back to the summary of the three types of Enterprise, Segment and Solution architect in Chapter 52, it becomes easier to see what TOGAF means by segment architecture.
All types of architectural role have responsibility for the planning, defining, documenting and managing some aspect of the architecture – it’s just at different levels of detail, scope and domain subject matter.
- The Enterprise Architect looks after the architecture at a landscape and technical reference model level. In other words – it’s a broad view across the whole of the enterprise. It’s a role that provides holistic overview and coordinates all views and viewpoints. Often the Enterprise Architect might also lead a team that consists of Segment and Solution Architects. Typically the enterprise architect relies on the segment and solution architects to provide detail, so that the enterprise architect can focus on how everything works together in a systemic, collaborative, synergistic way.
- The Segment Architect focuses on a specific aspect of the business or organization. They look up to the enterprise architect to provide the overall context of the work they do. But they also need to look sideways to other segment architects – to make sure that their segment fits with the architectures in those areas.
- The Solution Architect operates at a system or subsystem level – which often means that they are directly engaged in projects and architecture delivery. The solution architect is the one that knows the detailed information about systems, products, and technologies; for example, they might be the expert on data warehouse architectures. A solution architect looks to the segment and enterprise architecture roles to provide the contexts in which a detailed architecture fits.
The role of Segment Architect isn’t missing; it is more veiled or obscured. It is not obvious because architects are not typically given the title of Segment Architect. But when we search further we find that the distinction between “enterprise”, “segment” and “solution” helps to explain the key difference between the three types of architecture role.
Look within your enterprise and you will find plenty of examples that fit the Segment Architect type of architecture role.