Saying kanban is a task board with WIP limits is a bit like saying Lean Startup is about releasing buggy first version MVPs. It's cargo culting at best. Kanban is about keeping focus, creating quality gates, pull vs. push and so much more than just WIP limits. You can always limit WIP manually. How hard is it to simply choose to limit the WIP on a board column?
Your comment doesn't respond to what he said. He said that without WIP limits, you don't have kanban, while you responded to a statement that kanban is only task boards plus WIP.
The two are not equivalent. It is as if I said that without polite discourse you don't have a productive debate, and someone else called me an idiot for claiming that good manners and threaded comments are all HN needs.
Automagic WIP limits may not be necessary for imlementing kanban, but that's a deign debate, not a what-is-kanban debate. You may have a good point about whether WIP limits are necessary for a good "implementing kanban" application.
I disagree. I think WIP really needs to be a built in concept of a kanban app. The thing about WIP is it points out bottle necks and problems in your process quickly and concisely. It's pretty common for teams to go over WIP, and do it willingly, to allow the red flag the system produces to point out to the rest of the team the problem.
If you have to mentally keep track of WIP, inside each team member's head, you lose pretty much all of that.
Rigid rules means you can't adapt to reality. Adapting to reality is necessary for good software development.
Sometimes you just can't let something else wait until you are done with what you were doing. Sometimes you were doing something that can't meaningfully progress until something else has been fixed. Rigid computer enforced rules like that just mean that people will have to work around them, wasting energy and producing the wrong things.
WIP limits shouldn't be rigidly enforced. Instead a warning should show when you are over WIP, and some stats gathered in the background. If your team goes over WIP occasionally, it's usually fine. If you go over WIP a lot, your process is broken somehow. How, when, who and where you went over WIP can give you a lot of info on where your bottlenecks are and how to improve your process.
I've been on a Kanban team for the past year now and I can say with confidence that if our tool didn't track WIP, we would be less effective as a team.
