A basic Requirement is an AbstractRequirement

Apart from carrying an 'id' and 'text', the main purpose of AbstractRequirement is to integrate with the many supporting relationships and their operations (queries). These Properties are all derived from queries over the model: /derived, /derivedFrom, /master, /satisfiedBy, /verifiedBy, /refinedBy, /tracedTo:

In UML and SysML a '/' forward slash prefix before a Property name indicates that it is derived from other elements in the model.

In the Magic Model Analyst^® (Cameo Simulation Toolkit^®) tool (or in MagicDraw SysML Plugin if you have the Requirements plugin) you can initially just use the basic normative Requirement, or you can use one of the non-normative requirement types (more on those later):

SysML-1.6: 'The only normative stereotype based on AbstractRequirement is the Requirement stereotype, ... Examples of additional non-normative stereotypes based on AbstractRequirement are included in E.8.'

In the tool you can also easily convert (refactor) a basic Requirement into one of the out-of-the box "extended" requirements at any stage.

If the non-normative "extended" requirements don't fully meet your needs - or dare I say your "requirements" - you can extend those in turn to further customise them, or roll you own Requirements extensions, but any custom Requirements must similarly extend AbstractRequirement.

If you are just using the tool you'll never deal with AbstractRequirement directly.

Using just the basic Requirement type, we are going to explore next the relationships in the SysML requirements system.

Up next

Derived requirements and the DeriveReqt relationship

Notes

[TIP] In UML and SysML a '/' forward slash prefix before a Property name indicates that it is derived from other elements in the model.

[CAVEAT, TOOL] UML4SysML is a specification abstraction (concept) only, it does not find direct expression (such as via a namespace) in tools like MagicDraw/Cameo

Snippets (quotes/extracts)

[SysML-1.6] An AbstractRequirement establishes the attributes and relationships essential to any potential kind of requirement. Any intended requirement kind should subclass AbstractRequirement.

[SysML-1.6] Several requirements relationships are specified that enable the modeler to relate requirements to other requirements as well as to other model elements.

[SysML-1.6] The only normative stereotype based on AbstractRequirement is the Requirement stereotype, ...

[SysML-1.6] A requirement is defined as a stereotype of UML Class subject to a set of constraints.