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In the previous two posts in this series we introduced the core of the ArchiMate languages existing of the three layers and three columns. However, not all questions that enterprise architects typically face are supported by this core. Think for example about questions around security, risk and implementation planning. ArchiMate is an open standard that allows for the use of and even the extension of the language to support specific modeling issues. This can for example pertain to specific properties for an industry e.g. the financial sector, or support for a specific type of analysis that an organization uses.
This posting will elaborate on the two extensions were added to the ArchiMate specification in the latest 2.0 version: the motivation extension, and the implementation and migration extension. We will start this post by discussing these two extensions.
ArchiMate 2.0: Full alignment with TOGAF
TOGAF and ArchiMate are both Open Group standards. Together they provide full support for an enterprise architecture practice. TOGAF describes the steps to take with a number of phases (the ADM, or Architecture Development Method). For more information on the TOGAF and the ADM phases we refer to an earlier blog series on TOGAF that we published in the blog section of our website.
For each of the phases TOGAF describes what to do and also how to communicate the results with stakeholders. Better to use some kind of a diagram, or rather a matrix or table? TOGAF uses the concept of viewpoints to address this issue: What to communicate to whom, in what format and at what point in time. TOGAF does not prescribe how to actually put those viewpoints together in terms of a modeling language. And that’s exactly where ArchiMate comes in. The ArchiMate core allows enterprise architects to create baseline and target state diagrams for the business, information and technology architectures. Creating these diagrams are activities described in the ADM phases B, C and D. This is visualized in the figure above.
The “Motivation” and “Implementation and Migration” Extensions
The motivation extension adds concepts to the ArchiMate language that can be used to address “Why..?”-questions of an architecture. The concepts can be used to model the motivations that underlie the current and future design decisions for the enterprise architecture. Concepts in this extension are goals, principles, requirements, and constraints. Relations between these and core concepts can be modeled to show how the enterprise architecture addresses the issue modeled by e.g. a principle or a requirement. The motivation extension also includes concepts for stakeholders, drivers and assessments that can be connected to the other motivational concepts. This allows traceability from the level of a stakeholder all the way to parts in the core enterprise architecture. The concepts and relations of the motivation extension are depicted above.
The Implementation and Migration extension supports the process aspect of getting the enterprise architecture in place. It provides concepts to break this process down into programs and projects. If the scope of an enterprise architecture includes only smaller scale changes then one project or a program can be set up to go directly to the target state. Larger scale changes may be implemented gradually in a series of transitions. The Implementation and Migration extension supports such a temporal transition state with a concept called plateau. The gap concept represents differences between two plateaus, e.g. the baseline and the target architecture. Visualizing gaps in a diagram has in practice proven to be very insightful and can be used very effectively by architects to communicate about changes in the organization. The concepts and relations of implementation and migration extension are depicted above.
The figure below shows how the ArchiMate core together with the two extensions supports all the phases of the ADM.
As mentioned in the introduction of this post, ArchiMate can be customized in order to meet specific architectural needs and to allow for tool support for those needs. ArchiMate provides two mechanisms that support creating custom extensions: profiles and specialization.
Profiles can be used to enrich ArchiMate concepts and relationships with extra information. An example is to add to business service information about KPI metrics. Profiles can also be assigned to relations, for example to a used-by relation one could add the average number of use, enabling quantitative that could support sizing projects.
The specialization mechanism allows for the definition of new concepts based on existing ones. The new object has a more specific meaning than the existing one, and inherits all the properties of its “parent”. The figure below shows two examples of specialization.
Up to this point we discussed the key ArchiMate concepts, mechanisms and extensions. We would like to hear from you if you can think of situations where it is not obvious what ArchiMate concept to use or where you think ArchiMate misses concepts to model the situation. Please gives us a note and we are very happy to discuss the situation.
If you’d like to know more, please leave a comment. The next post in this series covers the tailoring of ArchiMate for optimal use in your organization. It is scheduled to be posted on 11th of June.
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