The impact of Lean Manufacturing on Environmental and Social Sustainability Performance

The interest of studying the relationship between lean manufacturing and sustainability comes from the popularity of lean production among companies and organizations’ increasing commitment to sustainability issues which are linked to operations management. This study aims at starting to clarify the complex relationship between lean production (composed four main bundles - JIT, TQM, TPM, HRM - and of a specific philosophy) and sustainability (considered in its social and environmental dimensions), through the investigation of lean impacts on sustainability performance and its interaction with sustainability action programs and the organization for sustainability (organizational responsibility and worker commitment). Literature provides some insight on this topic, but since contributions are often incomplete and sometimes contradictory, this study is composed of two main phases: a first exploratory phase conducted by means of five case studies; a second preliminary proofing phase, testing the relations through the International Manufacturing Strategy Survey. The first phase highlights a distinction regarding lean manufacturing, which has been split into two different constructs: “Soft Lean”, composed of lean philosophy (continuous improvement and waste reduction) and HR practices and “Hard Lean”, made of JIT, TQM, TPM. Starting from this distinction, both direct relationships (such as the impact of soft lean on the organization for sustainability; the impact of hard lean on sustainability performance; the interaction of the organization for sustainability on the relationship between hard lean and sustainability performance, which helps in solving some literature contradictions) and indirect relationships (such as the interaction between soft and hard lean with sustainability action programs) were found. Preliminary analyses of the second phase confirm the results highlighted through the case studies and show that interaction effects are more important than the direct ones: the interaction of lean manufacturing with other variables such as sustainability action programs or the organization for sustainability allows achieving better sustainability performance.