SYSML11 — SysML doesn't explicitly support the modeling of alternative models

SysML doesn't explicitly support the modeling of alternative models for example for trade studies as requested by the UML for Systems Engineering RFP. Models and Packages are not useful, because they don't allow to exclude elements. For example to specify a xor between requirements (if reqA is used, then don't use req B). Same for blocks and other model elements.

Discussion:
This issue was previously deferred by the SysML 1.1 RTF with the following
discussion at that time:
A full resolution of this issue is beyond the scope of an RTF. The issue is
being deferred, however, so that additional explanatory material could be
considered in a future RTF to clarify the scope of modeling supported by
SysML or to suggest possible workarounds. A full resolution of this issue
could be considered in an RFP for SysML 2.0.
Addition of support for modeling of alternative models was considered to be
beyond the scope of an RTF, so this issue is being closed. Requirements or
proposals to add such support can be considered under a future RFP.
Disposition: Closed, no change