Lean, Agile, and Six Sigma: Efficiency and the Challenges of Today’s World: Is It Time for a Change?

The article presents the results of research on the resilience of companies using management concepts such as Lean Management, Agile, and Six Sigma to the crises that companies have had to face in recent years: the COVID-19 pandemic, rising energy prices, and the war in Ukraine. The implementation of these management concepts should lead to process improvements and a reduction in the consumption of production resources, including energy. The aim of the study was to determine how these crises have affected the efficiency of companies and to determine whether the solutions used so far are sufficient or require modification. The authors used three research methods. Firstly, they analyzed the literature—scientific publications, studies, and expert reports. Secondly, they analyzed the financial results (net profits and share of Costs of Goods Sold in the value of Revenues) in the period before (2016–2019) and after the outbreak of the COVID-19 pandemic (2020–2023) of companies using Lean Management, Agile, and Six Sigma strategies and their combinations. To compare the effectiveness of these management methods, they also analyzed the financial results of international corporations and Polish companies. Third, they conducted a survey among Polish companies applying the Lean Management concept. The results of this research show that the crises of recent years, even if they caused a deterioration in financial performance, were short-lived as companies were able to adapt to the new conditions. Japanese companies using Lean Management increased their profits by an average of 55.56% between 2020 and 2023, and “Lean” American organizations even more (71.64%). Polish companies have been steadily increasing their profits for years (134.14% before the pandemic and 143.27% after the outbreak). The share of COGS will remain at a similar (high) level for many years to come. There are no significant increases in these costs due to crises in the companies’ environment (e.g., increase in energy prices), and, on the other hand, there is no tendency for them to decrease in a large proportion of companies. In the years 2020–2023, the largest decreases in the share of these costs occurred in companies combining Lean and Six Sigma (−11.85%). In companies that use the Agile strategy, there was an increase of 8.05%. However, these are average data, and the analysis of the results of companies from individual groups leads to the conclusion that it is not only the management concept that is important, but also how it is implemented in a given company. In addition, streamlining processes only by eliminating waste is not enough these days. It is necessary to use modern technologies (digital technologies, Industry 4.0). Increasing the efficiency of production or logistics processes leads to a reduction in energy consumption and external costs. However, new, specialized solutions are needed. The issue of energy efficiency is indeed gaining more and more importance in companies and is included in management concepts, e.g., in Lean Management.