Comparing the Toyota Production System and Lean

Pondering a decades-long confusion

Published: Thursday, October 5, 2017 - 11:01

I recently posted a version of the graphic below with the caption: “Not perfect, but close. It’s about right.” The response was overwhelmingly positive. A great majority of people recognized it as a unique comparison, one that they had never seen before, and also as an accurate comparison that effectively captures differences that actually exist.

My intent in producing the graphic was to address the decades-long confusion that has existed between the Toyota Production System (TPS) and lean, and to help people understand the critical differences. It was also to help people realize why they are often unable to achieve much success with lean despite a lot of effort over many years.

Figure 1: Comparison of Toyota Production System (TPS) and lean. Click here for large downloadable image.

Figure 1 presents factual differences and also shows how the interpretation of TPS by university researchers changed over time. My aim is to help people recognize how these differences shape the results that they achieve and how they effect people (particularly employees, as well as suppliers, customers, investors, and communities). 

Generic TPS

Nearly 30 years ago, lean was presented as the generic version of TPS. Actually, lean was an interpretation of TPS—a rather poor interpretation. Then, over time, lean drifted farther away from TPS, thus making it far less of a generic version of TPS and more its own unique thing. In other words, the interpretation of TPS got worse over time instead of better. It is clear that TPS and lean are not the same. The differences between the two are many and significant—especially in the details.

But, if “lean” is meant to be the generic version of TPS, then lean is obviously best represented by the red column in figure 1, TPS, not the blue columns. In other words, if lean is truly the generic version of TPS, then the ingredients should be nearly identical—but they are not.

Figure 1 does not argue against lean success or the useful learning that will come from it. It merely points out important differences between TPS and lean. Understanding these differences can, in turn, help people refocus their attention toward TPS and the “Toyota Way” (“continuous improvement” and “respect for people”).

Figure 1 is a high-resolution image that you can copy (click on image to enlarge and save). Click here to download a print-quality PDF file of the graphic. You can use the graphic to reflect on your own understanding of TPS and lean; in your training and teaching of TPS or lean; or to stimulate discussion and deepen the understanding of TPS and lean in your organization as well as between you and your suppliers. Perhaps it will result in needed corrections that help put you on a path closer to Toyota’s management practices so that you can achieve better business results and better outcomes for people.

The graphic includes several questions for you to contemplate:
• Why are there differences between TPS and lean?
• Why did lean drift further away from TPS over time?
• How do the differences affect outcomes?
• What is the impact on business results and on people?
• What should you do if your lean efforts don’t produce significant business results? Should you move toward TPS?
• In what ways does the graphic reduce confusion between TPS and lean?
• Toyota does not practice lean. Why?
• TPS represents actual business needs that are common among most businesses, while lean does not necessarily reflect actual business needs (for example: maximize customer value, perfect processes, and perfect value). Does lean reflect your actual business needs?

Can you think of other questions?

I’d like to leave you with a thought to ponder: Anyone can know lean, but nobody can know TPS.

© Bob Emiliani. First published Jan. 31, 2017, on Bob Emiliani’s Innovative Lean Leadership blog.

About The Author

Bob Emiliani

Professor M.L. “Bob” Emiliani is an engineer, researcher, author, historian of progressive management, educational reformer, and executive trainer. A long-time Toyota Production System (TPS)/lean practitioner he was the first to focus on lean leadership as an area of scholarly study. Prior to joining academia, he worked in industry for 15 years in engineering (R&D, new product development) and operations, including implementing TPS (manufacturing and supply chain). Emiliani is the author or co-author of 19 books, 48 peer-reviewed papers, and 540+ blog posts on lean leadership, management, organizational development, supply chain, materials engineering, and more. Emiliani has bachelor’s and master’s degrees and a Ph.D. in engineering.