XKE (Xebia Knowledge Exchange) of March was a chance to introduce the step of urbanization. Introduced example did not follow holding portray: a step of urbanization is adapted according to plans and organisations to which it is applied.
The purpose of this ticket is to unwind this step in a simplified way. It will give us the occasion to define the used vocabulary, and to make an official report on this step.
We will unwind example with an approach TOP-DOWN, that is the analysis begins with the definition of strategy to go down then through the different strata of YES. For example, we will take the case of a travel agency which buys and sells trips.

• Why a step of urbanization?
• At what levels is the step of urbanization?
• Identification of zones, districts and islets (= functional block)
• The deliverable

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Why a step of urbanization?

The step of urbanization is born in the will to have a progressive and not very expensive system of information. Indeed, most evolutions within one IF turn out to be expensive and often have an impact on the other components of the system, drawing away so problems of coherence and brakes in the improvement of the system of information. Moreover, constant evolution of IF procreates redundancies of functionality and overlapping of the fluxes of communication. In the final, they are with a system of not correspondent information with processes jobs of the organisation.
The step of urbanization allows to "line up " its system of information. It is a question of establishing or of r - to establish a relation between the computer systems and the strategy of the firm. Purpose being to be possible include progressively requests of evolutions of the system of information by a rational approach.

At what levels is the step of urbanization?

The step of urbanization touches all levels of the organisation:

Let us specify functions of the different layers:

• Seen job: cartography of processes jobs of the organisation.
• Functional view: description of functionality (services) given by the system of information to support processes jobs.
• Seen to be applicative: description of all the elements of the computer system implementing services urbanised in form of software elements.
• Technical view: description of the facilities of functioning of the software elements of the computer system.

On this diagramme, we see that the step of urbanization is principally applied at the level of views job and functional. In summary, step applies mainly to strategies of the organisation as well as to way they will be implemented.
Two last views correspond more to problems plans.

The analysis of strategy

In this first stage, objective is to define the main strategy which the organisation wants to attain, as well as the means to reach it. It is often made by means of one or of several diagramme (s). We take here as the model of a diagramme of Ishikawa:

This diagramme allows to represent reasons and their effects. The central arrow serves for representing main purpose, and reasons allowing to reach this target are represented by arrows run to the central axle, and so on for other arrows. Here, main purpose will be to improve functioning and profitability of the travel agency. For example, it will pass by the improvement of the productiveness of the sellers.

This or these strategies are accompanied by analyses of the existent functionality of the organisation by breaking processes down job. Let us take as model with the process of purchase of a trip by an agency:

This analysis is also accompanied by diagrammes of activities.

Then, after analysis, step plans to define target processes:

 

In this example, existent process was broken down into two processes to answer problems of the organisation better.

Identification of zones, districts and islets (= functional block)

Definitions:

• A zone represents functional domain.
• A district is an operation inside a job.
• An islet represents an application.

Let us see on an example one of the ways of identifying these:

Here, we have a service group who announce some with others, and we determine right away the problems of exchanges of flux and of redundancies
Step plans to separate these services and to regroup them according to functional domains. So, we get:

At this stadium, functional domains are identified and we see that communications between services pass by a zone of mediation (they speak then about functional d couplage). This zone allows to centralise the fluxes of communication. The layer mediation can, for example, be implemented by ESB. In summary, this one aims at assuring the interconnection by managing mediation, communication and correlations between services and applications of a system of information. For more precision, I invite you to consult our white book on ESB.
To note, the appearance of a reservoir of information, regrouping all data of the organisation.

Cartographies

Cartographies allow to have an overview of zones, districts and islets. Step recommends to establish the cartographies of processes jobs, functional and applicatives existent and target. The cartography of processes jobs was already recalled before. The applicative cartography is the logical continuation of the functional cartography and regroups therefore the elements of this last. We will stay over the applicative cartography. This stage represents the structuring of the system of information in applicatifs blocks.
By taking back our example, we get two cartographies so:

applicative existent cartography:

In dotted line, we have zones in which we have districts (in purple) and inside these of islets (in yellow). The names of islets are present for information only.
Across this cartography, we find problems seen before (redundancies )

applicative target cartography:

On one hand, we have a better cutting up, because an islet belongs to the single district and on the other hand we see that new zones appear.
This cartography comes from the target functional cartography on which zones were added. Of course, to set such cartography up, good practices exist among which (The plan of urbanization of IF, C.LONG P ):

• Any functional architecture includes a zone exchange which is in a way the catch of YES
• Any functional architecture includes a zone deposit of data: she regroups dynamic information as well as services of access to these data
• Any functional architecture includes a zone frame of reference of data: she regroups common information in the different elements of the system of information being relatively stable.
• Any functional architecture includes a zone of unique piloting
• Any applicative architecture includes a zone scheduling which assures interface between the forehead service, the back service and the middle service.

The deliverable

At the end of this step, a Plan of occupation of soil (POS) is defined. It is a constituted report:

• Of syntheses on directions chosen as well as justifications on discreet options.
• Of a definition of zones, districts and islets.
• Existent and target cartographies (cartography of processes, functional, applicative, and possibly technology).
• Additional documents (reports of discussions, list of persons and of organizational entities )

Purpose is to identify distances between the existent and the principles of urbanization, but also to establish the planning of evolutions by describing actions and their corresponding cost.

Conclusion

In practice, the step of urbanization is very heavy to set up. On one hand, she requests the participation of many actors of the organisation (DSI, strategical committee, MOA D CISIONNAIRE, MOE), and on the other hand, the analysis is very long. Main problem follows from it: needs often evolved and POS is not willy-nilly adapted any more
In theory, the main benefits of this step are to optimise the functioning of processes, to have a system of modular information, progressive and consistent and to make easier the reuse of components. Of course, as you suspect it, in view of the previous criticisms, these benefits are often utopian. Nevertheless, it is possible to reach by applying step to it to reduced perimetres (the single process for example) and in it rant.

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