Improving system capacity requires you to find the bottleneck; however, bottleneck detection is a tricky business. The main problem is that most bottlenecks are not static, but move around. In this post we will look at the behavior of bottlenecks on the shop floor. This is the first post in a series of posts on bottleneck detection. Subsequent posts will look at the flaws of commonly used methods to find the bottleneck and describe two new reliable methods for finding the bottleneck on the shop floor.
Christoph Roser
Culture of Quality – A Comparison of Toyota and GM Recalls
One of the main aspects of lean manufacturing is quality. This post discusses the differing attitudes regarding quality in different corporate cultures. In particular, the Toyota brake recalls and the GM ignition recalls are compared.
Toyota Employee Relationship Crisis and Countermeasures 1990’s
Toyota has developed what is probably the finest production system in the world, the Toyota Production System. There is general consensus in the rest of the world that its methods and philosophies can significantly improve efficiency and quality, to the point that anything Toyota does is admired and copied. Some practitioners seem to wear rose-colored glasses when talking about Toyota. However, like any company, Toyota does have its fair share of problems and mishaps to deal with, from the 1950 near collapse, to the US gas pedal recalls during 2009–2011. This post will discuss the employee relationship crisis at Toyota around 1990 and Toyota’s countermeasures.
How Many Kanbans? – Estimation Approach and Maintenance
In my previous two posts, I described how to calculate the number of kanbans (Post 1 and Post 2). However, this calculation is complex, and the result is nothing more than a very rough estimate. Hence my preferred method for determining the number of kanbans is, broadly speaking, “just take enough, and then see if you can reduce them.” In this post, I would like to explain this approach and also discuss how and when to update the number of kanbans.
How Many Kanbans? – The Kanban Formula, Part 2
This is the second post on kanban calculation (if possible, please read the first post on kanban calculation first). There are two possible approaches. First, you can calculate the number of kanbans using a kanban formula (due to its length, split into a first post and this second post). Alternatively, you can estimate the number of kanbans and adjust the system as it is running (as shown in a third post).
How Many Kanbans? – The Kanban Formula, Part 1
One frequent and tricky question when designing a pull system is to determine how many kanbans to use in the system. There are two possible approaches. First, you can calculate the number of kanbans using a kanban formula. Due to the length of the process, I have broken this into two posts (For the second part click here). Alternatively, you can estimate the number of kanbans and adjust the system as it is running (as shown in a third post).
Cost of Complexity
The cost of complexity can significantly impact the bottom line of manufacturing companies. According to A. T. Kearney, the top 30 companies in Germany could earn €30 billion more if they would reduce complexity, increasing their EBIT by three to five percentage points. After discussing the cost of complexity in a previous post, using the Maybach as an example, this post describes the general levers influencing complexity cost.
The Problem of Losing Kanban – Different Kanban Types
Pull production using Kanban is one of the major achievements of the Toyota Production System and hence lean manufacturing. The work in progress is limited by the number of Kanban. Overproduction is avoided by producing only if a part is taken out of the supermarket and the Kanban card is returned to the start of production. However, this Kanban system works only if the Kanban returns to the start of production. Losing Kanban means not reproducing goods sold. In this post I would like to talk about different methods to prevent the loss of Kanban, including different Kanban types.