View
Sources: “view” and “viewpoint” in IEEE Std 1471-2000. Cigref and Club Urba. A view presupposes that an actor looks at something. It gives access to one part of the observed reality, from the viewpoint of this actor. It therefore expresses subjectivity: the situation of the subject faced with the reality. Its advantage lies in communication as it establishes itself specifically compared to the needs and language of a certain type of actor.
Level
For a long time, methodology, notably with Merise, spoke in terms of levels of abstraction or levels of concern. These levels were clearly distinct from views, which were also defined, at the same period of time and in the same methods. So the levels were given as being more fundamental, more essential than views. These methods first defined levels as expressing the internal structure of the system. The views were thus defined secondarily in their relation to the actors and for communication purposes. For example, Merise distinguishes the “external views” from the data model. The data model provides the complete and normalized data structure, whereas the external views present an extract of it, potentially denormalized, for a particular use.
The term “level”, nevertheless, was unfortunate insofar as it infers a certain idea of hierarchy and therefore of value.
Aspect
It is evident, in any case, that we do need two notions. When we look at a cube, for example, we never see all the sides. We can form several representations of it, take several views of it, and we have to go around the object in order to detect all its sides.
When we look to fully represent the cube and to link the views, it is useful to know that this object has six sides, even if this idea does not come to us from experience but from understanding. Geometry comes before the geometric drawing.
The reference framework at the foundation of Praxeme targets the internal organization of the Enterprise System, regardless of who observes it. It is a prerequisite for mastering the mass of knowledge, information and decisions that concern this complex object. We try to extract its internal logic, prior to any methodological development and well before we tackle the questions involving the actors: responsibility, organization of the transformation, communication, etc. In so doing, Praxeme aligns itself in the continuation of Merise, in contrast with the Anglo-American methods, which, over the past decades, have retained only the notion of view and concentrated their efforts on communication to the detriment of the system’s internal logic.
In order to qualify these domains that structure the reality of the enterprise, regardless of the observer, Praxeme has chosen the term “aspect”.
Illustration of the difference between aspect and view
This distinction, essential for the theory of knowledge, is revealed in the use of both terms and in the qualifiers that accompany them. We will illustrate this, in this paragraph, using the intentional aspect as defined in the Enterprise System Topology. This aspect, the first in the order determination, gathers all expressions of the will of the enterprise: its values, its objectives, the requirements, the indicators (often intimately associated with the objectives) and its vocabulary. Praxeme does not impose a structure for this aspect. The method contents itself with distinguishing the types of elements of intention, leaving us to structure the aspect as we see fit. There is therefore an architectural decision to be made for the intentional aspect as well:
- either we structure it using the sources (the emitters or the original documents, often consisting of different types of elements),
- or we opt for a specific criterion, with a notion of domain as with any other aspect.
Thus, the intentional aspect has its own structure and obeys its own rules that do not necessarily reflect usage. Consequently, it becomes of interest to define some views that will facilitate communication with specific profiles of actors, for example:
- an ethical view, centered on the enterprise values and including how they impact on the other aspects of the Enterprise System;
- a metrological view, consisting of indicators, their links with the transformation objectives, as well as their projection towards the business concepts, the activities or any other type of element in the other aspects;
- a terminological view, expressed by the enterprise thesaurus and showing, in addition to the terms, the traceability links that connect them to the other elements.
The views are sub-products that answer the needs for communication and manipulation; they are therefore linked to uses. The method has to meet these needs without altering the logic of the internal structure of the Enterprise System. It obtains this by distinguishing both the notion of aspect and that of view.