SYSML21 — Semantics of flow-connections and control nodes is cumbersome and challenged to be supported graphically

Currently flow connections can be connected to control nodes such as decision/merge/fork/join using parameters, and the behavior needs to be explicitly specified like in any action. This is a limitation comparing to UML that allowed flows to be seamlessly connected to control nodes with proper semantics to cover such connections. In SysML V2 the current approach is to specify parameters on control nodes to handle this. There are two main issues here:

• Weaker expressive power comparing to UML/V1
• Challenging to support graphically with "opaque" symbols like fork or decision

The expectation is to provide proper semantics to connect flow connections similar to UML/V1, and keep the graphical symbols "atomic" without having to add compartments or parameters, at least for "default" use cases