The use of namespace containment to specify requirements hierarchies precludes reusing requirements in different contexts since a given model element can only exist in one namespace. Source OMG Systems Modeling Language (SysML) 1.6
Composite (a.k.a. "compound") Requirements Gallery Tutorial TRAIL: Webel's ultimate guide to Systems Modeling Language (v1) with MagicDraw/Cameo Section 16:01: Requirements engineering in SysML Slide kind SysML Requirement Diagram
An entire specification can be decomposed into children requirements, which can be further decomposed into their children to define the requirements hierarchy. Source OMG Systems Modeling Language (SysML) 1.6
A composite requirement may state that the system shall do A and B and C, which can be decomposed into the child requirements that the system shall do A, the system shall do B, and the system shall do C Source OMG Systems Modeling Language (SysML) 1.6
SysML-1.6: Refers to both 'composite requirements' and 'compound requirements' (clearly as identical concepts)
A composite requirement can contain subrequirements in terms of a requirements hierarchy, specified using the UML namespace containment mechanism. This relationship enables a complex requirement to be decomposed into its containing child requirements. Source OMG Systems Modeling Language (SysML) 1.6
Figure 16-5: Use of the copy dependency to facilitate reuse Gallery Tutorial TRAIL: The SysML-1.6 Hybrid SUV sample and specification diagrams in MagicDraw/Cameo (with annotations) [UNDERGOING UPDATE to SysML1.7] Section Section: SysML-1.6 specification diagrams: 16 Requirements Slide kind SysML Requirement Diagram
The diagram in Figure 16-2 shows an example of a compound requirement decomposed into multiple subrequirements. Source OMG Systems Modeling Language (SysML) 1.6
Figure 16-2: Requirements Derivation Gallery Tutorial TRAIL: The SysML-1.6 Hybrid SUV sample and specification diagrams in MagicDraw/Cameo (with annotations) [UNDERGOING UPDATE to SysML1.7] Section Section: SysML-1.6 specification diagrams: 16 Requirements Slide kind SysML Requirement Diagram
SysML-1.6: 'Figure 16-2: Requirements Derivation' indeed shows DeriveReqt but spec text refers to it only as 'an example of a compound requirement'
When a requirement has nested requirements, all the nested requirements apply as part of the container requirement. Deleting the container requirement deleted [deletes] the nested requirements, a functionality inherited from UML. Source OMG Systems Modeling Language (SysML) 1.6
Subrequirements shall be accessed through the "nestedClassifier" property of a class. Source OMG Systems Modeling Language (SysML) 1.6
The default interpretation of a compound requirement, unless stated differently by the compound requirement itself, is that all its subrequirements shall be satisfied for the compound requirement to be satisfied. Source OMG Systems Modeling Language (SysML) 1.6
Compound requirements can be created by using the nesting capability of the class definition mechanism. Source OMG Systems Modeling Language (SysML) 1.6
SysML: Webel recommends use of an additional custom «requirementGroup» stereotype for compound Requirements that serve as owning Namespaces and are subject to the satisfaction policy that all child requirements must be satisfied.
