The theory about this type of leveling is not very difficult. Unfortunately, hard facts of reality often nullify any possible advantage of this type of leveling. In fact, most of these types of leveling that I have seen were complete rubbish. They were a dog-and-pony-show to please management at the expense of performance and shop floor efficiency. In this post I will explain to you how it is supposed to work in theory. In the next post I will explain why it rarely works in practice .
One approach to leveling (also known as heijunka [平準化], or production smoothing) is capacity leveling: Do not add more production orders into the system than what the system can handle. Try to produce the same total quantity every day. Doable for almost everybody, and one of my favorites. In fact, if you are using a pull system like kanban or CONWIP, then you are already almost there.
This approach is not the highest and best form of leveling, but it is doable for almost all firms. Some other approaches, notably an Every Product Every Cycle (EPEC) approach, often do more harm than good.
Production leveling, also known as heijunka (平準化) or production smoothing, is one of the hottest topics in lean manufacturing. Successful leveling is considered one of the highest achievements in lean manufacturing. Unfortunately, if the production system is not ready for leveling, it also has lots of potential to make things worse. A lot worse! This is the first post in a longer series of post about leveling, where I will present different types of leveling and their advantages and disadvantages.
Eliyahu Goldratt developed different methods on how to manage production systems. These methods are nowadays known as the Theory of Constraints, or TOC for short. One key method described is called Drum-Buffer-Rope, or DBM for short. Similar to Kanban or CONWIP, it aims to constrain the work in progress (WIP) in the system. There is much discussion on which method is better than the other, although the result often depends heavily on with which method the respective author earns its living. In this post I will present how Drum-Buffer-Rope works, and discuss its advantages and shortcomings.
Bottleneck detection and management are important in managing or increasing your production capacity. In the first post of this series I talked about fundamentals and improving utilization. The second post looked at the impact of planning on the overall production capacity. This final post in the series will look at the effect of decoupling and the actual process capacity improvement.
Bottleneck detection and management are important when managing or increasing your production capacity. In the first post of this series, I talked about fundamentals and improving utilization. This second post looks at the impact of planning on the overall production capacity. A third post looks at Bottleneck Decoupling and Capacity Improvement.
In the past I’ve written a few posts with some nifty methods on how to find the bottleneck (The Bottleneck Walk – Practical Bottleneck and The Active Period Method), and some warnings of which methods don’t work. In this post I would like to go into more detail on what to do once you find the bottleneck! Due to the length of this topic, I have split it into multiple posts. This first post gives an introduction and goes into more detail about increasing utilization. The next post talks about planning. A third post looks at Bottleneck Decoupling and Capacity Improvement.
I occasionally watch the reality show Undercover Boss, where top executives work undercover in their own companies. Over and over again I see these managers making the same mistake: They have no understanding whatsoever of what is really happening on the front lines. It is a typical case of not going to the shop floor often enough, or in lean speak, no genchi genbutsu (Japanese for “go and see”). So, <dramatic voice> Why do bosses all make the same mistake? Will they ever learn? Will you enjoy this post? See for yourself in the post below! </dramatic voice>.