Yet another hot topic in lean manufacturing is visual management. This can be very helpful in running a shop floor, but when done wrong it can also be quite wasteful and embarrassing. In this post I would like to show you the basic principles of visual management with a few examples. There is more to visual management than merely putting lines on the shop floor.
The Basic Idea
Visual management aims to make the situation easily understood merely by looking at it. The goal is to get as much information as possible with as little observation or time as possible. Visual management complements well with the idea of going to the real place (Genchi Genbutsu). It also intertwines closely with 5S.
Like most topics in lean, you can use the English phrase Visual Management, or you can use the Japanese term. While I prefer English when speaking to an English-speaking audience, the Japanese term is Mieruka (見える化 with 見える or mieru for being able to see and 化 or ka for the action of making something).
Three Approaches to Visual Management
In my view there are different directions you can go with visual management. I will discuss them here in order of preference, with the best one at the end.
Visual Management with Data Displays
One common example is digital information displays, often called Andons (See also my post All About Andon and How to Use an Andon – and How Not To). On such information displays you can usually see the production rate, the quality defects, and the status of the machines.
It is also possible to put data on paper. Often this is printed, although I prefer handwritten data due to the better involvement of the workers (see The Advantage of Handwritten Data on the Shop Floor). Ideally, this data is shown graphically and easy to understand, using graphs, tables, diagrams, and colors.
The idea is again that the data is right there on the shop floor. This is useful if there is no easier way to visualize the system.
Visual Management with Markings
A lot of such markings are actually government regulated. For example, all fire- and emergency-related markings are examples of visual management.
Visual Management with Tools and Parts
The best type of visual management is if the information about the system can be seen in the system directly. If you create a graph or a data display, there is a chance that it is outdated or simply wrong. Whereas if you see inventory on the shop floor or tools in a drawer directly, the information is up-to-date, and less likely to be incorrect.
Common examples are tool drawers where each tool has its own location. You can see immediately which tool goes where and which tool is missing.
A similar approach is a shadow board, where the shadow of each tool is outlined. The shadow board here was used at Alcatraz prison in San Francisco. At the end of the shift, the guards could see immediately if all knives were returned, or if an inmate was walking around with a potential weapon.
I have seen similar shadow boards for knives in the food industry. The managers there worry less about murders, but they don’t want any tool to go missing and potentially end up in the products.
Visual Management using Layout
This can also be done with material. A good FiFo lane not only manages inventory but also shows you where your material is, how much more work there is, and many other details on your process.
Even the overall material flow can be visualized through the arrangement of the machines. A flow shop is so much easier to understand than a job shop, since the machines are arranged in the product flow. It is much easier to understand where the flow of material is hampered.
The image below is the shop floor at Trumpf, which I find particularly well organized and easy to understand.
As a counterexample here is an old smithy. Even though it is a much smaller space, it is much more confusing.
Of course, I have also seen flow shops that were built like a maze, and even the workers that worked there every day had difficulty understanding the material flow. Clarity and structure are not only nice to the pedantic German engineer (me), but actually do have benefits for understanding the system.
Similarly, it is possible to structure your inventories. A supermarket has a dedicated lane for every product. You know immediately how much you have of which material. You can even mark the supermarket with green and red to show when you may get into a critical low-stock situation. This is so much easier than having an unstructured warehouse.
Some Not So Good Examples!
Like everything, visual management can be done badly too. It is particularly easy to overdo it with the markings. The image on the left is staged, but similar examples can be found proudly advertised on the web.
This is overkill. There is no advantage in visual management for individual pens and scissors, especially if it is the personal desk (it may be useful if it is a shared workspace, but even then it may also be too much).
Also, for illustration here is the cabling of two different computer racks. See the difference?
Examples Outside of Manufacturing
There are also examples in other industries. For example, during surgery, used sponges and gauze are stored in an array of plastic bags or hung on hooks so it can be easily seen how many were returned. The number of surgical sponges after the surgery has to be the same as before, otherwise the surgeon has to go looking for the missing sponge. After all, you don’t want the patient to wake up with something extra.
For a more positive historic example, see my blog post on Visual Management during World War II – A Visit to the Lascaris War Rooms in Malta. You can find a lot of visual management ideas there before the use of computers. Quite nifty, and open to the public if you happen to be in Malta 🙂 .
Again, the goal of visual management is to understand the situation as quickly as possible merely by looking at the shop floor (or, as a second choice, data displays on the shop floor). So go out, make your factory easier to understand, and organize your industry!
P.S.: This blog post is based on a question by Prashant.