Enterprise-wide lean management systems: a test of the abnormal profitability hypothesis
Authors: Camuffo Arnaldo , Poletto Alberto 
Published: July 2023

PurposeThe paper tests if and to what extent lean management system adoption generates abnormal profitability, and how it accrues over time. Configurational approaches to lean management systems and “S-curve” effects in lean implementation are used to ground the paper's hypotheses and interpret its findings.Design/methodology/approachUsing the emerging view of lean as enterprise-wide management systems, this quasi-experimental study uses a difference-in-differences approach to estimate the abnormal profitability (ROIC) attributable to lean management system adoption. The paper leverages a unique data set of lean adopters nested in a panel data set (19 years) of 2,088 industrial firms matched by industry and firm size. It applies a variety of regression methods (two-way fixed effect panel estimator, propensity score matching, instrumental variable two-stage-least squares) to estimate the size of the abnormal profitability attributable to lean management systems, addressing endogeneity issues related to non-random sampling, omitted variable bias and reverse causation. It also analyzes the cross-firm variability of such abnormal profitability and how it accrues over time.FindingsFor the average non-adopter in the sample (44.3 million euro revenues), lean adoption generates abnormal ROIC ranging from 1.4% to 3.9%. These results come into effect approximately three years after starting lean adoption and peak after eight years. While the average abnormal profitability attributable to lean adoption is sizable, it varies significantly across firms and over time. This significant variation is compatible with firms' diverse ability to understand the complex inner workings of lean systems, and to design and implement them so that they improve profitability.Research limitations/implicationsThe conceptualization of lean as enterprise-wide management system can be further refined to more effectively categorize the components of lean systems and investigate the nature of their relationships. Lean system adoption measurement can be fine-tuned to better capture cross-firm and longitudinal heterogeneity. Future work can explore other dependent variables of interest to different stakeholders including shareholders' value, employment and environmental and social sustainability.Practical implicationsThe financial benefits of adopting lean can be reaped to the extent to which managers embrace lean as a philosophy and implement it pervasively in the organization. A firm can use the study's estimates as a basis for making calculations about the returns of investment in lean adoption. The paper also shows that “getting the lean system right” makes a significant difference in terms of abnormal profitability, which is twice as large for the best lean adopters..Social implicationsCompared with the promises of many lean proponents and supporters, the paper provides a more realistic view of what to expect from lean adoption in terms of profitability. Adopting lean as a comprehensive, enterprise-wide management system is not a universal panacea, but a complex endeavor, characterized by multiple complex decisions that require considerable capabilities, coordinated efforts and consistency of action.Originality/valueDifferently from extant research, this study does not study the correlation between the adoption of lean operation practices and financial performance but focuses on the abnormal profitability generated by the adoption of lean as a pervasive, enterprise-wide management system. Its research design allows to identify the differential profitability attributable to lean adoption and documents that it accrues non-linearly.