Model-Based System Architecture

Chapter 9Perspectives, Viewpoints and Views in System Architecture

Together with Matthias Dänzer, Bernafon AG.

9.1 Overview

Try to show more boxes and arrows in one single diagram than one can easily understand, then you may be able to reproduce a problem that P.B. Kruchten describes in the beginning of his article “The 4 + 1 View Model of Architecture” [81]. He addresses the problem of architectural representation that overemphasizes certain aspects of development while neglecting others. Kruchten's “4 + 1 View Model” was developed as a remedy to the problem. It is based on the approach of addressing different stakeholders' concerns with different views. The “4 + 1” views are the logical view, the development view, the process view, the physical view and the scenarios,¹ which tie the elements of the other four views together. Kruchten's work was targeted at software architecture. Nevertheless, the notion of separating different stakeholders' concerns via different views also holds for system architecture, as we have seen in Chapter 6.

The term view is known from Section 7.7, which is about the separation of view and model. A view in that sense is a general means of representing only as much of the available information as is practical. To distinguish it from views that offer specific details from the system architecture for addressing a given stakeholder's concern, we call the latter ones architecture views. Their role in architecture descriptions has been discussed in Chapter ...