SYSML21 — Optional Variation Point

In commercial practice, many variation points are optional meaning that its variants are present or not. A SysML v2 variation currently only allows its members to be its variants which are always identified with multiplicity 0 or 1 for an optional variation.  It is desired that a variation that is optional receive special treatment to facilitate its use by PLE methods and tools.  In particular, it is desired to provide a unique way to identify an optional variation and to enable it to include its features instead of its variant members.