TOGAF and ArchiMate come from the same stable – they are both EA standards managed and maintained by The Open Group®. But to what extent do they overlap or complement each other? How can they be used in combination? And how can we overcome any limitations they might impose?
Let’s start by clarifying what each provides:
- Although TOGAF is billed as an architecture framework, it could be more accurately described as a “body of knowledge” and a “framework of frameworks”. It is a body of knowledge describing some aspects of EA practice, with its strongest and most detailed content describing the process for developing architectures, the “Architectural Development Method (ADM)”. It also includes a set of frameworks covering areas such as capability, content, governance, and skills.
- ArchiMate is a formal, graphic language for describing or modelling architectures.
While neither provides a “complete” approach to Enterprise Architecture, ArchiMate and TOGAF actually complement each other rather well. TOGAF describes a process for developing architectures, which requires us to document the baseline, transition, and target architectures and express stakeholder concerns through views that show pertinent aspects of the architecture. On the other hand, ArchiMate gives us a modelling language, with a standard set of shapes and colours to graphically present these various views. Many senior practitioners will focus on delivering enterprise architecture with TOGAF and ArchiMate as part of a combined practice.
Both TOGAF and ArchiMate follow the basic concepts of EA that are defined in the ISO/ IEC 42010 standard. This standard describes concepts such as stakeholder concerns and viewpoints. These are constructs that are important in both TOGAF and ArchiMate.
The ISO standard also distinguishes between the architecture of a system and the artifacts created to document that architecture, the “architecture description”. Although it provides recommendations on what should be included in an architecture description, it doesn’t prescribe the form that it should take.
TOGAF, via the ADM and the various guidelines and techniques, offers a process for developing architectures. It also provides examples of various viewpoints and perspectives. In the Enterprise Continuum it describes the concept of a “virtual architecture repository” containing artifacts and reference models. While the ADM will never document the exact ways that every architecture team works, it is indicative of the key architecture tasks.
In contrast, ArchiMate doesn’t describe how we architect; it provides a formal way for documenting what we produce – the descriptions of the architecture.
Now you might say that this was already covered in the TOGAF Content Framework and Metamodel. In fact, there is quite a lot of overlap and similarity in the components described in TOGAF and those included in ArchiMate. At the high level, both divide EA into domains or layers: in TOGAF we have the business, information systems (data and application), and technology architectures, while in ArchiMate we have the Business, Application, and Technology Layers (the application layer includes the data and application domain).