Fluctuations are bad for manufacturing. In lean, unevenness is one of the three evils, besides waste and overburden. In this post I will give you an introduction to fluctuations. One option to handle fluctuations is decoupling, but this addresses only the symptoms and not the cure. In my next post I will show you how to actually reduce fluctuations.
Kanban (and pull systems in general) are a beautiful way to manage production. While the number of kanban cards should be verified periodically, for certain situations, however, it may be sensible to have additional kanban prepared. These extra kanban are added to the system on short notice to alleviate symptoms of other problems. However, please do not see this as a new and cool additional feature to your kanban system. Instead, if you have to use extra kanban, then something is going wrong. Such extra kanban are only an emergency fix and do not solve the underlying problem. Still, in some cases you do need an emergency fix. Let me explain: