By Taiichi Ohno
In this classic text, Taiichi Ohno–inventor of the Toyota Production System and Lean manufacturing–shares the genius that sets him apart as one of the most disciplined and creative thinkers of our time. Combining his candid insights with a rigorous analysis of Toyota’s attempts at Lean production, Ohno’s book explains how Lean principles can improve any production endeavor. A historical and philosophical description of just-in-time and Lean manufacturing, this work is a must read for all students of human progress. On a more practical level, it continues to provide inspiration and instruction for those seeking to improve efficiency through the elimination of waste.
The Toyota Production System, by Taiichi Ohno, describes the background and evolution of the development of the fundamental building blocks that make up Lean Manufacturing that we know of today. As these concepts are mostly common parlance, I will focus my review primarily on points made that I found unique or personally relevant.
It is very interesting to understand how Toyota developed the Lean Manufacturing process compared to the Mass Production system developed in the U.S. One may look at the negatives of mass production and decry how U.S. manufacturers made a long-term mistake and that the Japanese were uniquely prescient. However, history, culture, and political realities explain the reasons much better.
In simple terms, the U.S. enjoyed a long and stable age of prosperity that enabled manufacturers to build products in large quantities… and sell everything they could possibly make. A combination of growing incomes, revolutionary automobile technology, a large population, and a huge land mass allowed factories to open the floodgates in a rush to meet the demand. It was acceptable to make a large number of Model T’s. People didn’t require unique makes and models yet. The mass production process was the only way to meet the demand. As a result, a tight discipline on quality, inventory control, and labor efficiency were not required. Room for error and waste was possible in this model.
In contrast, Japan started out smaller, less stable, less wealthy… and was completely destroyed in World War II. From the ashes, demand was low and anyone who wanted to manufacture had to build infrastructure from scratch. The market needed automobiles and trucks, but mostly of different shapes, sizes, and purposes in order to meet the diverse demand to rebuild the Japanese economy. Out of desperation, manufacturers squeezed everything they could out of their assets and manpower. From this perspective, it became imperative to manufacture automobiles with these principles in mind:
- Build many types of models in small quantities
- Eliminate every bit of waste in the process. Stop the line if you find a problem.
- Make what’s needed at the time of the customer order
- Build labor processes and machinery that can switch from one model to another easily
- Establish continuous flow as the basic condition
- Base all decisions on whether cost reduction can be achieved
- Have the earlier process produce only the amount withdrawn from the later process
- Fix the process before relying on technology
- Turn movement into working
- Saving worker expense
The book packed a large number of concepts that changed the shape of manufacturing worldwide in a very small space. It is extraordinary that so much was gained from such a simple source. One could use this book as a useful pocket guide. Of course, a newer book like The Toyota Way by Jeffrey Liker probably handles the topic more thoroughly, but it is nice to read a book from one of the inventors so that you can see the thinking and perspective from the ground up.
With that, I intend to analyze three major points made in the book that resonated with me. They are:
- Use inverse, flexible thinking for better problem solving
- Build many types of models in small quantities
- Workers should operate more than one machine type
Ohno instructs us to use inverse, flexible thinking to guide our way to better problem solving. For every problem Toyota faced, there was already a mass production method to handle it. Ohno studied Henry Ford’s production techniques at great length. Yet, Toyota did not do that. They challenged the status quo and mustered the courage to re-shape an entire line of thinking.
Inverse thinking can help solve day-to-day problems at work. We are all familiar with processes that work reasonably well. Whole departments, performance reviews, management strategy, etc. are built entirely around these conventional processes. We all know how it feels when you look at one of these processes and feel in your gut that they just aren’t as good as they can be.
Once you try to fix these processes, the organization inevitably pushes you into a traditional direction to improve the process. They may want to add more people, create audit reports, integrate a new technology, or increase enforcement to improve the process. Yet, that is not what it needs. It needs to be questioned root-and-branch. Inverse thinking enables you to ask questions like:
- Does this process really need to exist?
- Do these people need to perform the process or can someone else?
- Why is it so complicated? Why does it take so long? Is it measured? How much does this process cost the company? Why does the process stop in the middle?
- What does the customer think of the process?
- Does it produce products or services that the company makes money from?
- How many people or departments are involved to produce the final output?
- Does management even know how this process works?
Only inverse thinking can break a company out of the status quo of a mundane, expensive, and unexamined process. The culture must accept regular reviews of the status quo that could make them uncomfortable. They may need to make sure that the output actually serves the customers’ needs. They may need to change departmental lines so that the process has more accountability in one group or under one manager. Somebody who is happy producing their part of the project may lose that responsibility. Yet, it must be done to improve delivery to the customer.
Recommendation: Look to see if your process improvement is ready to move to a new level of maturity. Use CMMI Capability Maturity Models as a guide.
Build Many Types of Models in Small Quantities
After World War II, the Japanese economy was in a desperate state where they simply needed to “build many types of models in small quantities”. This seems more relevant than ever today. Customers are demanding more and more customization in their products; sometimes even made-to-order. Companies must make something unique, yet still make the products cheaply and efficiently a la mass production. Production processes must be fit to handle different product characteristics on the same line or in the same office procedure. There should be very few instances where you are producing the same thing over and over unless you plan to be a low-cost leader for a commodity product.
In IT, Ohno’s philosophy pertains to building infrastructure. You should not have people building the same products over and over. Anything routine should be automated. Departments need to embrace automation of commodities and smooth out the process for handling exceptions. Outside of IT, departments need to learn how to automate themselves. They can either partner with IT or develop skillsets within their group who can create ways to eliminate waste.
Recommendation: Any department needs to know how to do Business Process Mapping to optimize their processes. Managers should know intimately how their department contributes to the production system as a whole. I’ve seen many managers who have no idea what their people or doing or what their product is. I’ve seen many more who may know the former, but certainly don’t know if they are executing well.
Workers Should Operate More Than One Machine Type
The last cherished point that Ohno makes is his insistence that workers be able to operate different types of machines instead of specializing in one. Inevitably, a worker running one machine will stand there watching it. Ohno designed an L-shaped layout of three different machines that worked in the process order. He felt strongly that people were perfectly capable of running these three machines. He still got pushback but felt that the concept was far more accepted in Japan than in the U.S.
This brings me to a personal sore point. I agree that specialists are needed for many subject matters. However, this inevitably creates silos in every organization. Specialists lose touch on how to interact with other specialists. Since passing a complex product from one specialty to another is “not their specialty”, huge handoff gaps occur throughout the process. In many cases, companies need to place expeditors, liaisons, or other operational roles in between these specialty areas just to keep the process moving. This is a huge waste, yet it is rarely acknowledged as such. As hiring people becomes more and more difficult, when a hiring does become possible, organizations inevitably seek the specialist since they are rare. Managers feel more comfortable when they have their own expert that can save them from potential disaster. Yet, they make no consideration for how a process needs to move through the system. Boundaries need to be broken and only a generalist or a multi-skilled operator can do that. In Ohno’s words, “In the Japanese system, operators acquire a broad spectrum of production skills that I call manufacturing skills and participate in building up a total system in the production plant. In this way, the individual can find value in working.”¹ In this way, Ohno demonstrates how each worker is part of a whole process and not just one step in the process. You can still have experts in house, but departments need to sprinkle generalists in the mix, people who have interest in multiple topics, who are willing to cross boundaries and learn new things.
Recommendation: Eliminate expeditors and middlemen, even abruptly, if possible. Though not covered in this book, Lean uses a metaphor called lowering the water level to see the rocks. By eliminating the middlemen, you see very quickly all the obstacles interfering with the process. It can be quite alarming. Many cultures are not prepared to do the work necessary to remove those rocks. However, it is critical to do so. You must design processes so that no management intervention is required to keep them moving forward. Identify inputs and outputs between every process step. Remove the rocks. Make it flow. Don’t let it stop!
This is the type of book that I will read over and over. I enjoyed reading the straightforward style and could see how and why Taiichi Ohno created the Lean system. It enables you to get grounded in the grass roots of the Lean Manufacturing movement. It gives you an important perspective and enables you to understand its original intent. You will then create the skills to assess the different evolutionary steps of the process and know more pointedly what each step was created for. It’s always good to go “old school”.
¹ Taiichi Ohno, The Toyota Production System: Beyond Large-Scale Production (Boca Raton, FL: CRC Press, 1988), p. 14.