Tag Archives: Inventory

How to Deal With Long Delivery Times

Lean has a bunch of advanced but good tools for material delivery, like Just in Time, Just in Sequence, and Ship to Line. Using them is much easier on short distances and with short delivery times. Yet, sometimes you just don’t have the option of short delivery times. This blog post deals with the issues related to long lead times and delivery times. Continue reading How to Deal With Long Delivery Times

What to Do with SMED: Reduce Lot Size or Increase Work Time?

SMED (Single Minute Exchange of Die) is a very useful tool to reduce changeover time. Reducing changeover time will free up time for other uses. Western management often wants to use this time to produce more goods. However, the rule of thumb at Toyota is to use this newly available time to do more changeovers rather than more products. This increase in changeover has the potential to significantly reduce the lot size, which often has much larger benefits than the additional work time. In this blog post I want to look in more detail at this relation between changeover duration, productivity, and lot size. Continue reading What to Do with SMED: Reduce Lot Size or Increase Work Time?

Toyota’s and Denso’s Relentless Quest for Lot Size One

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Just when you need it …

A famous step toward perfection in a lean production system is a lot size of one. However, few people realize what enormous effort and rigor Toyota applies to achieve this goal. During my visit to a Toyota plant and the APMS conference in Tokyo in 2015, I saw quite a few stunning examples of this quest. Let me show you … Continue reading Toyota’s and Denso’s Relentless Quest for Lot Size One

Can you tell your Bottleneck from your Inventory?

HourglassOn the shop floor it is common wisdom to find the bottleneck based on the inventory. If the buffer is full, the bottleneck is downstream. If the buffer is empty, the bottleneck is upstream. Is this true? My student Carolin Romeser and I spent quite some time verifying this, and found some interesting results. In general it is true, but … the devil is in the details. Continue reading Can you tell your Bottleneck from your Inventory?

How to Make “Just in Time” Work – Part 1

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Just in time

Just in Time (JIT) is the delivery of parts just when you need them. In my last post I explained what JIT is all about. In this post (and the next one) I will go into much more detail on different measures you can take toward JIT. But be warned, most of them are not easy, either in implementing or in convincing cost accounting about it beforehand. Continue reading How to Make “Just in Time” Work – Part 1

What Is “Just in Time”?

Just in time …

Just in Time (or JIT) is a powerful method to reduce costs and increase efficiency. However, it is also very difficult to achieve. Most times when a Western company tells me it does JIT, it turns out that this is merely wishful thinking. Let me tell you what JIT really is. I will also talk a bit about the history of JIT. Finally, I will show you a few negative examples of wishful thinking common in modern industry. In my next posts I will go into more details on how to make it work. Continue reading What Is “Just in Time”?

How Product Variants Influence Your Inventory

Array of carsThe sales & marketing department often aims to create more and more product variants to target even the smallest niche in the market. Yet, it is common wisdom that more variants also mean more inventory.

However, the relation is not quite as clear cut. In my last post I wrote about the Relation between Inventory, Customer Takt, and Replenishment Time. The relation is similar for variants, and it all depends on the ratio of the customer takt to the replenishment time.  Continue reading How Product Variants Influence Your Inventory