Analyze Performance (Constraint Diagrams, Timing Diagrams, Views)

The diagrams in this section of the example are largely Package diagrams that describe Viewpoints and Views used to address stakeholder concerns. The topics also introduce Measures of Effectiveness (MOEs) that can be used in trade studies to evaluate candidate solutions and architectures. The concepts of Viewpoint and View are articulated in ISO-42010 (formerly IEEE-1471) and the SysML Viewpoint and View constructs are consistent with this standard. Typical examples of Views include operational, manufacturing, or security, and these are then related to model elements.

The Viewpoint and View model are best thought of as a narrative or description model, which helps clarify and explain a system model. A Viewpoint and View model exposes elements of one or more system models. More specifically, a Viewpoint is a particular frame from which to view the system models and is a specification of rules for constructing a View to address a set of concerns that are of significance to stakeholders. For example a performance architect will have different concerns to a safety architect. The View is intended to visualize the system from the specified Viewpoint. This provides a mechanism for stakeholders to specify aspects of the system model that are important to them from their Viewpoint, and then represent those aspects of the system in a specific View.

The Viewpoint describes the point of view or lens through which a group of stakeholders look at a system model and, by framing the concerns of the stakeholders along with the method for producing a View, their concerns can be addressed. The method describes:

• The expectation of what stakeholder(s) want to see exposed from the model
• How the stakeholder wants the information to be structured and presented
• In what kind of artifact the stakeholder wants to consume the information.

In other words, the process is the set of rules that describe how the View should express the information from the model to address the stakeholder concerns. When the Views and Viewpoints are modeled in Enterprise Architect the relationship to modeling elements can be defined.