Requirement Diagram

The Requirements diagram is used to create and view Requirements and their relationships to other elements, including other Requirements. Requirements can be specified at any level, from strategic enterprise or business requirements through stakeholder requirements down to low-level engineering and even software and transition requirements. For more information see the SysML Requirements Modeling Help topic.

The elements contained in this diagram can be viewed in a number of different ways, including:

• Specification View - allowing the elements and their notes to be displayed in word processor or spreadsheet format in a separate dockable window
• Inline Specification View - allowing the diagram and a list of its elements in a narrative form to be viewed side-by-side
• List View - allowing the diagram elements to be viewed in a list that can be sorted and the elements grouped by properties
• Gantt View - allowing the diagram elements to be represented on a Gantt chart showing how resources are utilized over time

Elements

The main elements that can appear in Requirements diagrams are:

• Requirement
• Test Case

The main connectors that can appear in Requirements diagrams are:

• Containment
• Trace
• Copy
• Derive
• Verify
• Refine
• Satisfy

Tools

A variety of tools can be used with requirements modeling, including:

• Specification Manager - which allows a user to work with requirements in a spreadsheet or word processor type of format
• Spreadsheet (CSV) Import and Export - which allows content in spreadsheets to be imported or exported from the model
• Documentation - which allows formal or informal documentation to be generated from the model in a variety of formats
• Traceability - which provides a hierarchical view of an element's relationships to other model elements
• Responsibility Window - which provides a composite view of the important responsibilities of an element, including Constraints, Requirements and Scenarios
• Relationship Matrix - which allows the connections between Requirement (or other elements) and other elements such as stakeholder needs to be visualized in a matrix
• Mind Mapping - which provides a way of recording the progress of a meeting, thus recording - for example - the stakeholders' needs

Probably the most widely used of these requirement tools would be the Specification Manager, which will provide a welcome and familiar way of working with textual specifications such as requirements or constraints. The Specification Manager can be used to view a list of elements contained within a Package or a diagram.

Usage

The Requirements diagram can be used to show a hierarchy of requirements using the containment relationship allowing a viewer to see how the  structural relationships of the requirements. It is however most compelling when Requirements are viewed in a diagram with other elements using other relationships including other requirements. An example of this is the relationship between Requirements and Test Cases or Requirements and the Components of a solution.