When you’re trying to understand the functions that an organization performs, you’re not interested in what application components are hosted on what servers. When you’re trying to comprehend the supporting software stacks of your applications, it’s not useful to consider the motivation model of your external stakeholders. Sure, these other questions can be important, but the human brain can only hold so much information in play at one time, which makes it necessary to focus on whichever immediate question that that model is being used to answer.
So viewpoints are an extremely useful technique for breaking a model into sufficiently small components that the model becomes useful. The international standard ISO 42010 provides a well-known, rigorous treatment of viewpoints and how they address specific concerns of specific stakeholders. At the same time, frameworks and standards such as TOGAF and DODAF and ArchiMate suggest a wide variety of viewpoints for use in this endeavor, as do other, less well known publications. However, these publications need to be applicable to every organization, so they propose a large number of viewpoints. This becomes a problem in that the personnel working on the model, and those consuming the views of the model need to invest time in becoming familiar with the concept of viewpoints, the viewpoints that are being used, and how the views they define display information.