ArchiMate

ArchiMate Core Framework.

The main concepts and elements of the ArchiMate language are being presented as ArchiMate Core Framework.[16] It consists of three layers and three aspects. This creates a matrix of combinations. Every layer has its Passive structure, Behavior and Active structure aspects.

ArchiMate has a layered and service-oriented look on architectural models. The higher layers make use of services that are provided by the lower layers. Although, at an abstract level, the concepts that are used within each layer are similar, we define more concrete concepts that are specific for a certain layer. In this context, we distinguish three main layers:[1][8][17]

• The Business layer is about business processes, services, functions and events of business units. This layer "offers products and services to external customers, which are realized in the organization by business processes performed by business actors and roles".
• The Application layer is about software applications that "support the components in the business with application services".
• The Technology layer deals "with the hardware and communication infrastructure to support the Application Layer. This layer offers infrastructural services needed to run applications, realized by computer and communication hardware and system software".[4]

Each of these main layers can be further divided in sub-layers. For example, in the Business layer, the primary business processes realising the products of a company may make use of a layer of secondary (supporting) business processes; in the Application layer, the end-user applications may make use of generic services offered by supporting applications. On top of the Business layer, a separate Environment layer may be added, modelling the external customers that make use of the services of the organisation (although these may also be considered part of the Business layer).

In line with service orientation, the most important relation between layers is formed by use relations, which show how the higher layers make use of the services of lower layers. However, a second type of link is formed by realisation relations: elements in lower layers may realise comparable elements in higher layers; e.g., a ‘data object’ (Application layer) may realise a ‘business object’ (Business layer); or an ‘artifact’ (Technology layer) may realise either a ‘data object’ or an ‘application component’ (Application layer).

• Passive structure is the set of entities on which actions are conducted. In the Business Layer the example would be information objects, in the Application Layer data objects and in the Technology Layer, they could include physical objects.
• Behavior refers to the processes and functions performed by the actors. "Structural elements are assigned to behavioral elements, to show who or what displays the behavior".[17]
• Active Structure is the set of entities that display some behavior, e.g. business actors, devices, or application components.

ArchiMate Full Framework

The Full ArchiMate framework is enriched by the Physical Layer, which was added to allow modeling of “physical equipment, materials, and distribution networks”[17] and was not present in the previous version.

The Implementation and Migration Layer adds elements that allow architects to model a state of transition, to mark parts of the architecture that are temporary for the purpose, as the name says, of implementation and migration.

Strategy Layer adds three elements: Resource, Capability and Course of Action. These elements help to incorporate strategic dimension to the ArchiMate language by allowing it to depict the usage of resources and capabilities in order to achieve some strategic goals.

Finally, there is a Motivation Aspect that allows different stakeholders to describe the motivation of specific actors or domains, which can be quite important when looking at one thing from several different angles. It adds several elements like stakeholder, value, driver, goal, meaning etc.

The generic elements are distributed into the same categories as the layers:[18]

• Active structure elements
• Behavior elements
• Passive structure elements
• Motivation elements

As described earlier in the Layers section, active structure element represents an entity that is capable of performing behavior. Based on two levels of abstraction[17] that ArchiMate provides, it is possible to distinguish between internal active structure elements, which stands for active elements within the system like f.e. business actors and external active structure elements which stands for elements that carry out the behavior outside the system - f.e. interfaces.

Behavior elements can be internal or external as well. Internal behavior element is the one that stands for an activity carried out by some active structure elements within the system. Archimate defines f.e. Process and Function elements. External behavior a service that the whole system provides to the environment.

Passive structure element is an object, that can be used by the behavior elements (and thus active structure elements can perform behavior on them). They usually stand for information objects in the business layer and data objects in the application layer, but they may also be used to represent physical objects.

As described in the previous chapter, Motivation elements are answering the question Why?, they are trying to give a context and explain the motives behind the architecture. They can be of an active structure, as a Stakeholder and also of a passive structure - Value, Meaning, Driver, etc.

ArchiMate sets several types of relationships that can connect different sets of source and target concepts. The classification of relationships is following:

• Structural relationships – create a static construction of concepts of the same or different types
• Dependency relationships – define how elements can support other elements
• Dynamic relationships – model behavioral dependencies
• Other relationships

[19]

Core concepts of the ArchiMate language (Lankhorst, 2013).

The general structure of models within the different layers is similar. The same types of concepts and relations are used, although their exact nature and granularity differ.

First, it is necessary to distinguish the structural or static aspect and the behavioural or dynamic aspect. Behavioural concepts are assigned to structural concepts, to show who or what displays the behaviour. For example, role, interface and collaboration are assigned to business process, organisational service and business interaction, respectively.

Second, there must be a distinction between an external view and an internal view on systems. When looking at the behavioral aspect, these views reflect the principles of service orientation. The service concept represents a unit of essential functionality that a system exposes to its environment. For the external users, only this external functionality, together with non-functional aspects such as the quality of service, costs etc., are relevant. Services are accessible through interfaces, which constitute the external view on the structural aspect.

Although for the external users only the external view is relevant, the design of organisations or systems and their internal operations and management also requires knowledge about the internal realisation of the services and interfaces. For this realisation, it is necessary to make a distinction between behavior that is performed by an individual structural element (e.g., actor, role component, etc.), or collective behavior (interaction) that is performed by a collaboration of multiple structural elements.

The ArchiMate separates the languages concepts from their notation (contrary to the UML or BPMN). As there are different groups of stakeholders, they may need different notations. This might be confusing, but it is solved by the viewpoint mechanism.

Although ArchiMate doesn't stress the only one notation, it comes with one and it aims to those "used to existing technical modeling techniques such as ERD, UML, or BPMN, and therefore resembles them".[17]

In ArchiMate, the use of colors is not explicitly set, however, it is usual that colors are used to distinguish between the different layers.

• Yellow for the Business Layer
• Blue for the Application Layer
• Green for the Technology Layer

[17]

As another way to distinguish to which layer which element belongs, according to the Full Framework layers, there can also be a capital letter in the left top corner of the element that stands for the specific layer (M for the Motivation, B for the Business, etc.)[17]

The shape of elements helps to distinguish the right Aspect. Structure elements have square corners, Behavior elements come with round corners. Diagonal corners indicate a motivational element.[17]

• Ensures consistency across all architecture models (business domains)
• Allows the stakeholders to be involved in design, to assess all the requirements and it works well as a communication tool
• Richness of the tool – core framework, motivation extension that enriches the core with reasons why and implementation and migration extension
• It is regularly updated with quite broad base of certified users
• 3.0.1 version supports IOT features
• It provides user with viewpoints

[22]

Some of the concepts are more useful than others, and some of the motivational concepts have been found confusing and/or duplicative, according to finished research.[23][24][25] Like other related content frameworks (e.g. the TOGAF content metamodel introduced in TOGAF 9), the framework covers a number of layers including both business and technology. The business layers can be harder to model because the concepts there are perhaps less tangible. However, this difficulty is not restricted just to ArchiMate. [26]