SYSML11 — Section: 16 Requirements

The nesting of requirements has the semantics that the upper requirement is fulfilled if all it's sub-requirements are fulfilled. In addition we need a mechanism to express a xor between sub-requirements sets to support variant modeling. If a requirement can be satisfied by different system components, these system components have different technically requirements. These requirements are sub-requirements, but a subset of them that relates to one of the system components is sufficient to fulfill the upper requirement. It is not necessary to fulfill all sub-requirements

Discussion:
Issue may be accomplished by modeling style (e.g. use package containment for
“x-or” instead of requirement containment). No need to encumber SysML with
Boolean operators for requirement satisfaction or containment.
Disposition: Closed, no change