Lecture 2 - Archi Mate - Appunti della lezione PDF

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ArchiMate ArchiMate has over the years become a rich environment that covers many aspects of modeling in Enterprise Architecture. It started out as a simple language to model informationheavy enterprises, focused on modeling the relation between ‘the Business’ and ‘IT’. It is what you use to model an actual enterprise: its processes, roles, actors, IT, physical equipment and facilities and so forth. It’s an integrated design with several views. It facilitates governance of IT and change management. We want to define systems interacting with each other. The levels of interaction in architectures are: We can have different architectures: at an organizational level or between organizations.

We are going to refer to ZACHMAN who provided definitions of framework based on aspects and perspectives and we’re going to use ARCHIMATE (OpenGroup modeling notation). Zachman’s framework corresponds to the primitive interrogatives: What, How, When, Who, Where, and Why. We’re going to focus on the “Core” (what, how, where, why) of the architecture and on some of the perspectives. We want to focus not only on elements but also on relations across a given perspective (horizontally) and also vertically (how they are related). In this way we’ll be able to describe a system. The correspondent of ArchiMate layers are the perspectives in Zachman’s framework. Describing coherence • What: Information architecture • Application • How applications are related: process architecture • Product architecture is relevant to understand how the applications provide the service We need to have these representations connected.

Main core elements and relations In yellow we have the business perspective. The active structure is the element able to perform services. In this case I the subject, a person that will be represented with his role. The process is represented by the verb, the behavior and it can be composed by more processes. Labels are important. Passive structure is represented by an object, on which the action is performed. Assignment relation is the dot with the arrow (from john to reads).

To start with, you need to know that almost all of ArchiMate is built from three types of elements: • elements that act: active (structural) elements • elements that represent the behavior of those ‘elements that act’: behavioral elements • elements that cannot act and which are acted upon by that behavior: passive (structural) elements The three element types, connected by relations, can form sentences of sorts. It tells the reader the basic structure of the story: who acts on what.

We’ll mainly focus on technology infrastructure; we want to describe an IT system.

Application and Business Service notation A service is a (formal or informal) contract between a consumer and a provider about the provision of defined goods and/or services. The contract specifies the duties and obligations for both parties. The premise is that the consumer of the goods or service finds some value in using the service, and the provider obtains some benefit too in providing the service. There are two way to represent the element and it’s true for all the elements. They are equivalent.

Arrows can have different endings, that means different things. Of course, we need to add details to this very abstract representation. For each of these services there are elements that characterize them.

Example Roughly, the two yellow and two blue elements in the image together make up the ‘application’ and the green element is the data the application operates on; i.e. think of it as the blue and yellow elements representing the word processing application and the green element representing the document being edited*. The lower three elements represent the internals of the application (blue & yellow) and the data (green). The two upper elements represent how the application can be used by and is visible for (exposed to) a ‘user’, the externals. One of the most essential aspects of ArchiMate is that modeling the behavior is separated from modeling the structure. The blue elements in the figure represent the active structure (’who’) and the yellow elements represent the behavioral aspects of the ‘who’ elements — they are two sides of the same coin: in a certain sense one can’t exist without the other. Service Oriented approach: • Components (business, application, technology infrastructure) provide services to other components • Services at all levels Examples • Web services • In cloud computing: Software as a Service (SaaS), Platform (PaaS), Infrastructure (IaaS)

Service Oriented Architecture: services are there to be used and we can call them also dynamically. If I’m a service provider I have to make my service available somewhere.

The three main layers of the ArchiMate language are: Business, Application and Technology. We’re providing services to customers. To provide the business service we need to organize the work, and this can be done through business processes. To support business processes, we need some software components (application services) which are realized through application components. Terminologically we have not to see that business process is a process because the arrow on its right already says it.

The main element types • Application Component: it stands for the ‘actor’ that an application in your actually is. It is one side of the coin of which the Application Function (its behavior) is the other. It’s a set of functions. •

Application Function: it stands for the ‘behavior’ of the Application Component, how the application can act. It is one side of the coin of which Application Component is the other. which represents the different functionalities realizing a given service. (create a doc, edit a doc, etc).

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Data Object: it is what the Application Function acts upon. The Application Function might create, read, write, update or delete the Data Object. Conceivably, the Data Object might not be needed. This is not the file or the database itself — those are represented on a lower level: the Technology level.

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Application Interface: it stands for the route via which the application offers itself to the business or to other applications. Note: both separate concepts (used by people and used by other applications) are supported by this one element. It is unlikely that the same interface will be used by both a human or another application, but it can be.

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Application Service: it stands for the ‘visible’ behavior of the Application, how the Application Interface can act for a user. It is one side of the coin of which Application Interface is the other side. Here again, the service may be ‘technical’ in that it is offered by one application to other applications or it may be part of your Business-IT integration: services offered to business processes (behavior of humans).

Now, apart from the elements, there are relations between the elements. There are four in the initial image: • Access relation: it always depicts a behavioral element accessing a passive element. •

Composition relation: it means that the element at the end with the diamond is the parent of the element on the other end and that the child cannot exist independently from the parent. This relation could also for instance be used to show that an Application Component has various subcomponents.

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Realization relation: it means that the element at the end without the arrowhead is the element that ‘creates’ the element at the end with an arrowhead. The application’s internal functionality realizes a service, which is the externally usable functionality of the application.

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Assignment relation: it means that the side with the dot (the active element) performs the behavior that is the behavioral element on the side with the arrowhead.

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Serving relation (‘Used By’) It means that the element at the end without the arrowhead serves the element at the end with the arrowhead.

Here we see a connection between the service layer and the business layer. Register Order is served by the order Recording. Or you can read it from the bottom: the payment service provides a service to the pay invoices.

The actual human actor, the one that fulfills the Business Role, it looks quite the same and that is not a coincidence. The relations are the same as with the application image above. If we want to completely describe the business layer, we need to say who is going to take the responsibility of this business process, that could be the company or a BU providing it. To perform the business process, we want to say what are the application service serving the business process.

The new element types are: • Business Role. The Business Role is an ‘actor’ in ArchiMate, but it is slightly more complicated than that, because it is an abstract sort of actor based on ‘being responsible for certain behavior’. The real actors are people and departments and such. •

Business Process. It stands for a set of causally related activities that together realize services or create something. Roles can be assigned to a Business Process, they perform the process, just as the Application Component performs the Application Function.

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Business Object: the (generally) abstract element that is created or used by a Business Process. Think of objects like ‘a payment’ or ‘a bank account’ or ‘a bill’.

Again, just as with the application, these elements can make sentences of sorts:

Example – TEL TEL is a phone company interested in improving the services offered to its customers. It wants to develop a new service than can provide real-time usage and billing information to users, based on an information portal for managing the process. New software is developed for this purpose. The new application resides on a dedicated server. Data about usage and billing are stored and elaborated in the company in two other different infrastructures (one for usage data and the other for billing data). These data are exposed as infrastructural services so that the application can access them.

Portal node layer indicates that there is a physical infrastructure.

In particular, the process enabled by the new system is as follows: the user logs in the portal, then she can select an item to inspect from the menu and she can view the dedicated page. This is the architecture before but with more details.

On one hand we have the business that offers services to others, on the other hand we may have IT that offers supporting services to the business (View 5). So, now we can fill with missing link.

How each element can be characterized Business Actor: in a business architecture there are of course real actors: people, departments, or even business units or companies or maybe regulators. ArchiMate has an element for that: the Business Actor.

Business Process Components: we put event only if they are important for us (if they are explicitly mentioned in the text).

You can represent the application function inside application component, keeping in this way the weakest relationship. These two are equivalent representation.

Technology Infrastructure Layer The Application Service to be able to be performed, the Ap- plication Function needs (IT) infrastructure to run. •

The node: it’s a computational or physical resource that hosts, manipulates, or interacts with other computational or physical resources. Think of it as a generic piece of IT infrastructure hardware combined with its system software, where files are stored, or applications can run.

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The Technology Function: it’s collection of technology behavior that can be performed by a node.

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The Technology Service: an explicitly defined exposed technology behavior, the visible behavior of the Node. In many ways, this is what the infrastructure is all about, what it can do for the applications, its reason for existence. For example, a ‘file share’ or ‘application execution’ or a ‘database service’.

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The Technology Interface: a point of access where technology services offered by a node can be accessed. It says it might be best thought of as a kind of contract that the ‘user’ (the application) has to fulfill. An example would be a protocol, like the SMB or NFS.

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Device: a physical IT resource upon which system software and artifacts may be stored or deployed for execution.

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System Software: it provides or contributes to an environment for storing, executing, and using software or data deployed within it

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A physical IT resource upon which system software and artifacts may be stored or deployed for execution

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Software that provides or contributes to an environment for storing, executing, and using software or data deployed within it. We want to know how things are connected. It’s not just about internet but about any type of network specified in the text.

Nesting There are four relation types that may be drawn by nesting an element inside another element: Composition, Aggregation, Assignment and Realization. These are the socalled structural relationships. Infrastructure components: DBMS: software element (4:04-4:08 second part)

Trigger and Flow There are two ‘dynamic relations’: Trigger (

)and Flow (----)

‘Portfolio Management’ is taking investment decisions, which result in orders for the ‘Trading’ function. So, ‘Trading’ starts trading when it receives an order from ‘Portfolio Management’. Triggering means there is a causal relation between the two functions. The flow between ‘Portfolio Management’ and ‘Trading’ says information flows from one to the other. In this case it is the ‘Order’. But the Trading function also regularly receives a list of allowed counterparties, countries and currencies from the ‘Risk Controlling’ function. This information Flows from one to the other, but it does not Trigger a trade. A Flow relation between two Business Functions could also be modeled as Business Objects written (Accessed) by one function and read (Accessed) by another:

Linking Infrastructure components • Communication network • LAN – Local Area Network • Internet There also other possible connections. If the nodes are not connected you cannot exchange data.

Modeling the infrastructure:

Example – TEL The new application resides on a dedicated server (portal node), together with an operational database used by the application for temporary data. Data about usage and billing are stored

and elaborated in the company in two other different infrastructures (one for usage data and the other for billing data). These data are exposed as infrastructural services so that the application can access them. The application is connected to each infrastructure by a LAN....