Kanban is the new silver bullet?
Kanban is about signaling. I need a new beer because my current one is almost done, I need some more stories to test because almost all stories are tested or even bring me my new bathtub because I almost removed my old one!
Signaling creates flow which is the number one driver for reducing costs as it reduces delays, rework and excess inventories.
Kanban is also about limiting work in progress or WIP. Your next beer is ready, I will not make you a new beer because it will get warm before you drink it. I will not code any more stories because by the time you test them and find a bug it will take me lots of time to resolve it and more bugs can have accumulated. I will not bring you a new bathtub because you did not finish removing the previous one and have nowhere to place it.
Limiting WIP is the number one driver for decreasing lead time because it limits transaction costs and absorbs variation in demand more easily.
Kanban is also about improvement. Now that I have only one beer ready for you, I see that you are getting drunk and will not make you any more beers. No that I stopped coding user stories I see that testing is a bottleneck and lots of bugs are returned for fixing. Now that you cannot place you bathtub anywhere I see that we are not communicating properly.
Kanban is just an approach to realize a pull system. You can also realize a pull system without Kanban.
Using Kanban to limit WIP and exposing your bottlenecks is a great approach. You can get a real map of how work is done currently and it gives you a good indication for potential improvement areas.
There is a catch though as there always is.
It does not tell you if you are doing the right thing! And therefore with Kanban or any other approach, you could end up doing the wrong thing better!
And as Russell Ackoff tought us
“It is far better to do the right thing wrong than to do the wrong thing right.”
So using Kanban to improve your system without understanding the work as a system and redesigning it from that view will not result in any significant improvements.