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 modelling. 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. Modelling 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]. See Figure 1.

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. Figure 2 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:
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Identification of enterprise entity
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Identification of the associated stakeholders (effective way is to use the onion model as discussed in MDA Radar, Article #13 – Enterprise Stakeholders)
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Identify the concerns
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Identify the viewpoints
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Derive the views based on the identified viewpoints
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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:

Figure 3 depicts the above-mentioned enterprise views. 
Figure 3: The Modelling 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 gaining currency by concentrating on different enterprise views. Hence, these architectures are mostly silent about their ‘views’ in the discussion. 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. Figure 4 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.
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