The release of Christoph Roser’s new book All About Pull Production inspires John Shook to discuss the origins and true meaning of “pull” and why it is incorrect to blame JIT for the shortcomings of global supply chains.
Guest post by John Shook based on his foreword in my book, and also a Cross-Post with Planet Lean. Many thanks, John!
A minimum level in a supermarket gives you a warning that a stock out is imminent. Hopefully it also gives you enough time to prevent such a stock out, even though this may result in firefighting. In my last post I talked on how to use a minimum level. This post will look at how to determine a good minimum level.
The kanban formula (or estimation) helps you determine the number of kanban. All of these should fit in the supermarket, hence the maximum in the supermarket represents all kanban. Many supermarkets also have a minimum inventory level. Unfortunately, there is little information on how to set the minimum. Time to take a deeper look on how to set and use the minimum level in the supermarket. In this first post I will look at how to use a minimum level in a supermarket. The next post will look at how to determine a good minimum level.
The kanban system is the most famous way to establish a pull system. As part of their guidelines for kanban, Toyota has established Six Rules for Kanban. They can be found, for example, in the 1973 Toyota Production System Handbook. This blog post describes these six rules, based on the Toyota handbook. While these rules are all true, they are in themselves not sufficient to establish a kanban pull production. Nevertheless, this post will show you these six rules.
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:
Kanban and similar pull systems like CONWIP or POLCA are basic parts of lean production. They limit the maximum number of parts by attaching a sort of token (i.e., the kanban card) to the part, and return to the beginning when the part leaves the system.
These kanban can be physical cards or digital representations. In this post I look into when you should use a physical kanban and when you should use a digital kanban.
While Toyota did not invent the pull system, they did invent kanban, the genius idea of using cards of paper (and later other forms of information) to create a pull system for mass-produced goods. I recently was able to take pictures of Toyota kanbans, and would like to show and explain them to you.
In my last post I described how to prepare for the implementation of a kanban system. This post goes into more detail on the actual change to the new kanban system. You surely know that every part should have a kanban. But what do you do if you have more kanban than parts? What do you do if you have more parts than kanbans? Find the answers below.