One of the key techniques described in TOGAF’s Architecture Development Method (ADM} is the Gap Analysis. TOGAF’s key argument for using this technique is to ensure, in the designing of a target architecture, that we take note of where we could be omitting some building blocks by accident or perhaps where we didn’t define some of the new building blocks required for the target architecture to ensure successful implementation. The architect, in her consideration of business or data architecture domain gaps needs to take into account how application or technology building blocks will be impacted, eliminated or created. Gaps in strategy or customer experience, among other dimensions also need to be considered and models related to those aspects need to be developed as well.
TOGAF provides a simple template to do the inventory of the gaps. It’s proposed in the form of a matrix (vertical axis describes baseline architecture building blocks, horizontal one, describes target architecture building blocks). This matrix focuses only on ABBs (architecture building blocks). However, we also need to know the context for such a gap analysis. For example, how the building blocks depend on or interact with one another is also of prime importance if we want to build real architecture roadmap useful for the implementation of target architecture.
An actionable architecture roadmap contains a set of work packages in the form of logically-sequenced solution building blocks (projects or tasks) after we have evaluated their dependencies. The TOGAF Gap Analysis Technique, however, doesn’t directly contribute to the process of translating the ABBs into Solution Building Blocks (SBBs) that takes place in Phase E of the ADM after we have documented candidate architecture roadmap components (ABBs) from the ADM’s Phases B, C and D.
If the architecture roadmap we intend to build remains at such an aggregation level of the sunset diagram like the one below, then the simple gap analysis matrix can feed it. However, at this highly abstracted level, it is a only a useful view for briefing stakeholders operating at a helicopter-view level of the architecture. Such a diagram will provide only limited value for building actual architecture roadmaps with detailed work packages containing all the required and inter- related building blocks.
What TOGAF doesn’t define is the necessary requirements traceability between ABB and SBB views. In other words, it leaves this important action to the architect’s discretion. A more complete approach to Gap Analysis would consider the architecture landscape in such a way that gaps will be measured and categorized, such as by relative importance, size, and risks. Architecture viewpoints that can better depict such information are critical to advise the progression from candidate ABBs to selected and sequenced SBBs.
Because the enterprise ecosystem is so complex, cohesive designs can be best achieved through team-based processes, so collaboration and enterprise-wide commitment to the Enterprise Architecture Management (EAM) capability is essential. Therefore, the level of maturity in EAM is a Critical Success factor (CSF) for deriving value from EA for enhanced IT investment decision making and in building an adaptable architecture runway.
Authored By Alex Wyka, EA Principals Senior Consultant and Trainer