In its never-ending quest to improve its production, Toyota has identified the three evils of any manufacturing system: waste (muda), unevenness (mura), and overburden (muri). In this post I will explain the concepts behind these three banes of manufacturing.
One popular and well-known concept of the Toyota Production System is the elimination of waste, in Japanese also called muda (無駄). It is one of the three evils of manufacturing systems, the others being unevenness (mura, 斑) and overburden (muri, 無理). In this post I would like to go through the details of waste with you. This includes the traditional seven types of waste – of which I am a big fan. For completeness sake I also included a lot more types of waste I have come across in industry. However, you have to decide yourself if these additional wastes are not themselves a waste.
Over Christmas I escaped the cold weather in Germany and relaxed on the warm beaches in Cuba. Of course, being a lean expert, I was also interested in the Cuban economy. As a communist economy (or more precisely, a socialist economy), it is based on centralized planning. In comparison, the capitalist system of the US (and most of the rest of the world) leaves most business decisions to individual entrepreneurs. This is somewhat similar to push and pull in manufacturing. Push systems also rely on centralized planning, while pull systems have their signal from inside the system to match the customer demand. As capitalism outperforms communism, pull usually outperforms push. Hence, in this post I would like to show you the shenanigans that happen in Cuba due to the effects of centralized planning. Warning: Lots of images ahead!
Inventory is one of the seven types of waste. There is usually quite a significant cost associated with having inventory, usually much more than what traditional bookkeeping accounts for. Between 30% and 65% of the value of your inventory is spent every year as inventory-related costs! This post looks into more detail at the cost of this inventory.
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.
One popular approach to battle waste is to streamline changeovers. Changing machines from one setup to another is often a time-consuming exercise. Hence, in lean manufacturing, reducing changeover times is a well-known method for improving efficiency. This post will show a number of examples where these quick changeovers (also known as SMED) can be practiced in an unusual environment.
In the previous post, I explained the basics of a quick changeover. In this post, I will go through the history of quick changeovers (also known as SMED). It is quite interesting to learn how things have developed during the twentieth century. The next post will look at different, unusual ways to teach SMED.
There are thousands of things to see during a plant tour. However, if you really want to know how good the plant is, there are a couple of tricks on what to watch during the tour. This post will give you a few quick but reliable metrics to estimate the performance of the plant.