The Kanban the author is using is "software development Kanban", not "lean manufacturing Kanban". There is a subtle but useful distinction. Most of the people w

The Kanban the author is using is "software development Kanban", not "lean manufacturing Kanban". There is a subtle but useful distinction. Most of the people who use TPS-derived methods in IT are actually using models that were adapted over time in software development lifecycles. The names are the same, but they're actually different processes. (I find this annoying too, I'm just giving context for why this is) A more accurate term for the author's board may be "Scrumban", but I'm not a Scrum or Agile expert by any means. You can use e-mail as a sort-of pull-based JIT system. You're constantly getting new resources, but you can't necessarily use them all immediately or action them all at once. So you stage the work in planning, and "pull" work into "doing" when you're ready. The lifecycle continues until an item ends up "completed" and archived. I don't think work-in-progress is all that difficult to manage with e-mail, as your e-mails are basically feature requests or alerts that lead to a story, and once the story is planned and ready for working, you can determine what a suitable work limit is. The author's e-mail model may need a bit of modifying to create actual stories rather than just tracking an e-mail, which may not be enough in itself to begin working on.