What the heck do kanban have to do with project management? Speaking -as- a Lean Six Sigma Black Belt (still can't type that with a straight face) in the health

What the heck do kanban have to do with project management? Speaking -as- a Lean Six Sigma Black Belt (still can't type that with a straight face) in the healthcare sector, I can't even imagine how someone would set out using a kanban to run a company. That's just so wildly divorced from what it is or what it's for that that article made no sense to me.