Scientific thinking is a cornerstone of lean thinking, but the lean movement itself has unfortunately become largely unscientific. Here are ten academic lean papers you should know.
Most writings on lean are anecdotal success stories or opinion pieces written by the ones responsible for deploying lean or the consultants consulting them. For both, vested interests is an obvious problem. Many seem to forget that the entire lean movement was born out of a scientific benchmarking study of the automobile industry in the 1980s (the MIT International Motor Vehicle Program), resulting among other things in the book The Machine That Changed The World (Womack, Jones, and Roos, 1990).
In the spirit of lean practice, scientific thinking should also be the basis for the lean school of thought. This post ranks ten of my all-time favorite lean papers from the academic literature. Not all these articles are strictly scientific in the sense that they present testable predictions, but they have hardly any bias problems, all are published in reputable journals, and all have been scrutinized through a peer-review publication process. I warmly recommend them for anyone searching more scientifically based insight and evidence on lean.
#10 Holweg (2007) – The history of lean, JOM
Matthias Holweg’s article “The genealogy of lean production” provides an excellent introduction to the historic development of the Toyota Production System and the subsequent birth of lean. Based on extensive expert interviews and reviews of the literature, Holweg distills a helpful historic timeline of the development of lean. (1296 citations in Google Scholar, 460 citations in Scopus.)
#9 Hopp and Spearman (2004) – Pull and push, M&SOM
Among the most important, used and misused concepts in lean thinking is “pull and push”, which includes key lean techniques like just-in-time, supermarkets, and kanban. In the discussion piece “To pull or not to pull: What is the question?”, Wally Hopp and Mark Spearman (who also coauthored the massive work Factory Physics) explain in simple language what pull production is and what it is not. Did you for example think that pull means make-to-order and push means make-to-stock? That is a common misconception, and makes this paper a must-read. (491 citations in Google Scholar, 208 citations in Scopus)
#8 Åhlström and Karlsson (1996) – Aligned lean enterprise, IJOPM
The paper “Change processes towards lean production: The role of the management accounting system” was selected because it was among the first to highlight the central role of accounting in lean transformations. Pär Åhlström and Christer Karlsson, two pioneers of lean thinking in Scandinavia, report results from a qualitative field study in a Swedish company. They conclude that yesterday’s accounting systems (that ironically largely remain the systems of today) are poorly aligned with lean thinking. In fact, accounting systems that follow old cost center rules are destined to work against lean implementation. While this article focuses on the role of accounting, the issue is a larger one: the whole enterprise from R&D to sales and marketing must be aligned for lean to work well. With the example of accounting, the authors show that this is a massive challenge. (134 citations in Google Scholar, 46 citations in Scopus)
#7 Ferdows and De Meyer (1990) – Cumulative capabilities, JOM
The groundbreaking article “Lasting improvements in manufacturing performance: In search of a new theory” by Kasra Ferdows and Arnould De Meyer is usually sorted as an operations strategy article, but it is just as much about lean production. Companies that embark on a lean journey without understanding the fundamental ideas offered by this article will struggle to prioritize resources efficiently and achieve sustainable results. In brief, the article propose the theory of cumulative capabilities that holds that companies can achieve operational excellence by building capabilities cumulatively rather than trading them off against each other. Doing so, requires a fundamental focus on getting quality right, then dependability (reliability and accuracy), then speed, and finally reducing costs. Many companies have not bought into the idea and focus most heavily on cost reduction. I should note that the subsequent research that have tested this theory find mostly support for the “quality first” argument, while the right sequence of the other capabilities remain debated. (1331 citations in Google Scholar, 619 citations in Scopus)
#6 Spear and Bowen (1999) – Importance of scientific thinking, HBR
One of the latest “rediscoveries” in the lean popular literature seem to be the importance of scientific thinking in Toyota’s practice (c.f. Toyota Kata) and conducting quick cycles of experiments (c.f. lean startup, or agile). Considering the massive heritage from the quality gurus, it is surprising and disappointing that it had lost traction in the first place. Steven Spear and H. Kent Bowen are not to blame, as their Harvard Business Review article “Decoding the DNA of Toyota Production System” explicitly argued for the importance of scientfic thinking to Toyota. They concluded that the goal of TPS is to create “a disciplined yet flexible and creative community of scientists who continually push Toyota closer to its zero-defects, just-in-time, no-waste ideal”. (1707 citations in Google Scholar)
#5 Shah and Ward (2003) – Lean as bundles of practices, JOM
If I got $1 every time the definition of lean is discussed, I would be a wealthy man. Lean remains an ill-defined phenomenon and thousands of authors have tried to come up with better and clearer definitions of lean. Most fail, with an exception of the seminal article “Lean manufacturing: context, practice bundles, and performance”. Based on a rich data set from the 1999 Industry Week Consensus of Manufacturers survey, Rachna Shah and Peter Ward derives statistically a definition of lean as a set of four “bundles of practices”: Just-in-time (JIT), total quality management (TQM), total preventive maintenance (TPM), and human resource management (HRM). (993 citations in Scopus). Although, it shouldn’t be taken as universal definition of lean, it is clearly among the most accepted ones in the academic literature. (2122 citations in Google Scholar, 993 citations in Scopus)
#4 Bloom et al. (2011) – Proving that lean matters, QJE
There is abundance of research that claims a positive association between lean implementation and positive effects on operational and finical performance. The problem is that close to all of this research, if put under scientific scrutiny, cannot really prove that lean matters. Showing scientifically that lean works is a massive challenge that few studies have solved. One excellent exception is the article “Does management matter? Evidence from India” by Nicholas Bloom and his coauthors, published in the Quarterly Journal of Economics. In this unique piece of research, the authors conducted a controlled field experiment among 29 Indianan textile industry factories, treating some of them with expert advice on lean production. It concludes that lean management practices increased productivity by 17 % the first year and had other long-term positive effects. Obviously, the paper is limited by its focus on lean implementation in one sector in India, but it is one of very, very few studies that robustly prove that lean practices help improve performance. (769 citations in Google Scholar, 148 citations in Scopus)
#3 Krafcik (1988) – Birth of lean, MIT SMR
No list of the top scientific lean articles would be complete without the one that introduced the word lean for the first time: John Krafcik’s “Triumph of the lean production system” published in MIT Sloan Management Review. The article does a terrific job in debunking the big myth at that time (still prevailing in some companies today): Lean does not only work in the cultural setting of Japan, but is a management philosophy that can be exported to any country. John Krafcik was at the time part of the MIT IMVP team. On a side note, Krafcik has had an amazing career in industry and is today the CEO of Googles autonomous vehicle company Waymo. (1436 citations in Google Scholar)
#2 Sugimori et al. (1977) – Kanban, IJPR
While all of the other papers on this list ended up being mostly management-related papers, this timeless article represents the industrial engineering soul of the Toyota Production System. Y. Sugimori and coauthors’ article “Toyota production system and Kanban system: Materialization of just-in-time and respect-for-human system” was published in the International Journal of Production Research in 1977, a year before Taichii Ohno’s book on TPS was published in Japanese(!). Although the paper is a source of the myth that lean fits best in Japan, it does a great job in explaining the key concepts that made Toyota outcompete its western competitors (including an early description of Kanban). A must read. Note that the third author of this paper is Fujio Cho, the current honorary chairman of Toyota Motor Corporation. (1289 citations in Google Scholar, 583 citations in Scopus)
#1 Shook (2010) – Creating a lean culture, MIT SMR
In any top ten list, one needs to take place one. I choose this article by John Shook, which has been one of my personal favorites since it was published in 2010. In “How to Change a Culture: Lessons From NUMMI”, Shook reports from his many years within Toyota and the Toyota-GM joint venture plant in California. Based on ethnographic first-hand observations he provides a very compelling theory on how a lean culture must be created: “It is easier to act your self to a new way of thinking, than to think yourself to a new way of acting”. In other words, to succeed with creating a lean culture, managers and workers must simply start doing something and learn from that rather than going through endless cycles of big talk. (154 citations in Google Scholar, 58 citations in Scopus).
Which lean papers did I miss?
This list represents my best attempt at listing ten excellent scientific articles on lean. I have deliberately picked papers that together provide a broad and good basis for understanding lean and that will help succeeding with lean in practice. Note the span width of the selected articles, which shows how different inductive, abductive, and deductive methods are needed to develop a field; in this case including historical reviews, interviews, ethnographic studies, case studies, quantitative survey analyses, and empirical field experiments.
Of course, there are several essential papers that I could have included. Although I have read quite a few lean papers, I obviously have not read them all. For example, it would be a good alternative to take a broader view and include research on themes related to organizational learning, organizational behavior, dynamic capabilities, change management, process innovation, production engineering, supply chain management, and other related themes. I will leave that up for discussion.
References and links for the top-10 lean papers
- Shook, J. 2010. How to Change a Culture: Lessons From NUMMI. MIT Sloan Management Review, 51 (2), 63-68.
- Sugimori, Y., Kusunoki, K., Cho, F. & Uchikawa, S. 1977. Toyota production system and Kanban system Materialization of just-in-time and respect-for-human system. International Journal of Production Research, 15 (6), 553 – 564.
- Krafcik, J. F. 1988. Triumph of the lean production system. Sloan Management Review, 30 (1), 41-51.
- Bloom, N., Eifert, B., Mahajan, A., McKenzie, D., & Roberts, J. 2011. Does management matter? Evidence from India. The Quarterly Journal of Economics, 128(1): 1-51.
- Shah, R. & Ward, P. T. 2003. Lean manufacturing: context, practice bundles, and performance. Journal of Operations Management, 21 (2), 129-149.
- Spear, S. & Bowen, H. K. 1999. Decoding the DNA of Toyota Production System. Harvard Business Review, 77 (5), 95-106.
- Ferdows, K. & De Meyer, A. 1990. Lasting improvements in manufacturing performance: In search of a new theory. Journal of Operations Management, 9 (2), 168-184.
- Åhlström, P., & Karlsson, C. 1996. Change processes towards lean production: The role of the management accounting system. International Journal of Operations & Production Management, 6(11): 42 – 56.
- Hopp, W. J., & Spearman, M. L. (2004). To pull or not to pull: What Is the question? Manufacturing & Service Operations Management, 6(2), 133-148.
- Holweg, M. 2007. The genealogy of lean production. Journal of Operations Management, 25 (2), 420-437.
This article is written and reproduced with the kind permission by Dr. Torbjørn Netland who is a Tenure Track Assistant Professor and the Head of Chair of Production and Operations Management at the Department of Management, Technology, and Economics, ETH Zurich, Switzerland. You can access his latest content through his website or follow him on LinkedIn and Twitter.