This paper identifies four problems with UML activity diagramming that have implications for teaching and practice. Solutions to each of the four problems are provided. The proposed solutions are borrowed from existing modeling paradigms, specifically structured systems analysis and design methods (SSAD). We did not see the need to reinvent solutions when adequate remedies exist. The proposed solutions help to improve the syntax, semantics, and consistency of activity diagramming in UML.
Grant, Delvin, "35. Improving Activity Diagramming with UML 2.0" (2010). CONF-IRM 2010 Proceedings. 30.