MDA Radar

Issue #14 [May 22-May 26]

Enterprise Views: The Kaleidoscope of the Enterprise

Within any enterprise architecture, concerns of stakeholders are considered the most important as it effectively drives us to consider different ‘views’ and ‘viewpoints’ that finally shape the real picture of the enterprise architectural landscape. A ‘view’ is what we see at a particular point of time, whereas a ‘viewpoint’ is what we are looking from at that particular point in time. Therefore, time alongside stakeholders become another important parameter to get a right view. This is why it becomes important for the enterprise architectural governance or the “master plan” to consider situations like “was”, “as-is” and “to-be” in every respect, leaving aside situations like “should-be”, “needs-are” and “could-be” as optional. We will be discussing more about these situations in the upcoming editions of MDA Radar. This edition will answer the question, “Why do we get different colors to our enterprise architecture landscape kaleidoscope?” It will effectively discuss the views required to conclude our trio series on Entity, Stakeholders and Views.

View: The Magical Window

Enterprise architecture is a developed landscape in terms of the enterprise business problem solution. It is eventually a ‘view’ representation of the entire system from the stakeholders’ perspective and realization of the associated set of concerns.

These views are the input criteria for any enterprise architect to design the right enterprise architecture. The same holds good for system architects, technical architects and information architects. “To decrease the apparent complexity of the resulting enterprise models, GERA provides the view concept that allows the operational processes to be described as an integrated model, but to be presented to the user in different sub-sets (model views) of an integrated model. Views contain a subset of facts present in the integrated model allowing the user to concentrate on relevant questions that the respective stakeholders may wish to consider using enterprise modeling. Different views may be made available highlighting certain aspects of the model and hiding all others. The concept of view is applicable for models of all entity types across their entire life cycle. Modeling views are generated from the underlying integrated model. Any model manipulation (any change of the contents of a particular view) will be reflected in all relevant views and aspects of the model.” [GERAM]





Figure 1: Views and Viewpoints: IEEE 1471-2000 based adapted representation

In a similar context, it can be said that a ‘viewpoint’ covers the concerns of the enterprise stakeholders, which eventually realizes into specific views. Therefore, viewpoints are generic in nature and can be considered as reusable assets for any enterprise. Based on the enterprise strategy from time to time, new viewpoints needs to be added or removed. On the other hand, a view is a concrete representation of particular viewpoints and therefore does not provide much reusability from an architectural design perspective. The ‘view’ versus ‘viewpoints’ relationship can be compared to object oriented class concepts, where ‘viewpoints’ are abstract class-typed and ‘views’ are concrete class-typed. The following figure depicts the relationship between views and viewpoints:





Figure 2: View versus Viewpoint relationship

Therefore, any type of architecture is the implementation of the associated views at that particular level. A successful enterprise architecture is the result of the following few steps:

  • Identification of enterprise entity
  • Identification of the associated stakeholders (effective way is to use the onion model as discussed in MDA Radar, Article #13 – Enterprise Stakeholders)
  • Identify the concerns
  • Identify the viewpoints
  • Derive the views based on the identified viewpoints
  • Implement the views

The success of enterprise architecture is therefore a careful consideration of the blend between views and viewpoints, and their successful implementation thereof.

Enterprise Views

The efficiency and strength of any enterprise architecture is effectively reflected by its views and viewpoints support. Enterprise landscape reaches its perfection with the existence and guidance towards more views. GERAM defines the following high-level enterprise views:





The following figure depicts the above-mentioned enterprise views:





Figure 3: The Modeling View concept. Four essential view types and their contents. Image Source [GERAM]. Used with kind permission of P. Bernus

GERAM does not recommend deriving all these views in every single entity architecture representation scenario. At the same time GERAM also recommends that we extend these views as required. For example, an economic model could be derived in the case of an economic value driven enterprise architecture.

Enterprise View Refinement

There are many enterprise architectures available in the market and surprisingly some of them are mostly silent about their ‘views’. However, TOGAF acknowledges the existence of multiple views in order to create a coherent enterprise architecture specification. The views recommended by TOGAF synergize with GERAM's views. The following figure briefly depicts this synergy:





Figure 4: Enterprise view refinement

GERAM recommends that views could be further refined to create more specific views as required. TOGAF has identified more than 30 useful views. These views are extremely useful for any specific enterprise architecture development.

Conclusion

In this week’s discussion we introduced the concepts of enterprise view. These ‘views’ constitute the main building blocks for the actual enterprise architecture implementation. Identification and implementation of ‘views’ is one of the most important success formulas for any enterprise architecture.

References

  • [GERAM] GERAM: Generalized Enterprise Reference Architecture and Methodology. Version 1.6.3 ( http://www.cit.gu.edu.au/~bernus/taskforce/geram ) also in P.Bernus, L.Nemes and G. Schmidt (Eds) Handbook on Enterprise Architecture, Berlin : Springer (2003) pp 22-64
  • [IEEE] IEEE Recommended Practice for Architectural Description of Software- Intensive systems. Institute of Electrical and Electronics Engineering Std 1471-2000
  • Handbook on Enterprise Architecture, Berlin : Springer (2003) by in P.Bernus, L.Nemes and G. Schmidt (Eds)
  • A Survey of Software Architecture Viewpoint Models by Nicholas May
  • [TOGAF] TOGAF (The Open Group Architecture Framework) Version 8.1 "Enterprise Edition". Available from http://www.opengroup.org
  • http://www.opengroup.org/architecture/togaf8-doc/arch/p4/views/vus_intro.htm