Author here. Thanks for the discussion.<p>UML didn&#x27;t pick up for whatever reason and visual programming fell into the valley of deception. I expect that with more UI&#x2F;UX research we can get to the plateau of productivity in the next decade.<p>Btw, there is a variant of UML that is executable. <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Executable_UML" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Executable_UML</a>