How Much to Adjust the Pull Inventory Limit

In my last post I looked at the behavior of the supermarket inventory for different kanban systems. In this post I will use this information to estimate how much the material availability of a system changes if you increase or decrease the inventory limit of your pull system (i.e., number of kanban).

Parts of this blog post are loosely based on chapter 13.2 of my new book All About Pull Production: Designing, Implementing, and Maintaining Kanban, CONWIP, and other Pull Systems in Lean Production.

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Behavior of a Kanban Supermarket

Setting up a kanban system is tricky, especially determining the number of kanban. The kanban formula is at best a rough estimate. It is usually advisable to adjust the number of kanban as the system is running. In general, if you have too much inventory, reduce the number of kanban. If you run out of material – and the cause is a lack of kanban – then increase the number of kanban. However, this general recommendation can be refined a bit by looking at the supermarket inventory. Let me show you how to improve your kanban system by analyzing your supermarket inventory.

This blog post is loosely based on chapter 13.2 of my new book All About Pull Production: Designing, Implementing, and Maintaining Kanban, CONWIP, and other Pull Systems in Lean Production.

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Performance Comparison of Job Shop and Flow Shop

Buckau Lathe DepartmentJob shops are, in their nature, much more chaotic than flow shops. Previously, I have written a lot on this topic. In this post I would like to take a deeper and quantitative look at this effect. Using simulations, we take two systems and try to make them as identical as possible – except that one is a flow shop and the other is a job shop. This blog post is based on a thesis by my student Daniel Ballach.

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What Is a Good Minimum for the Supermarket?

An empty standard EUR pallet
Prevent a stock out!

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.

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How to Use a Minimum in a Supermarket

Warning: Toilet Paper Stock Out Imminent!
Warning: Toilet paper stock out imminent!

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.

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Reducing Lead Time 3 – Throughput and Lot Size

Traffic JamTwo more factors for reducing your lead time are the throughput and the lot size. However, the throughput has a smaller effect – although with other benefits that are often larger than the reduction in the lead time. The reduction in the lot size can have a huge effect, although usually only for make-to-stock production. Nevertheless, both are worth looking at if you want to reduce the lead time.

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