Sustainable Lean Management Practices: Net Zero Win-Win Green Value Stream: A Case Study of Metal Product Manufacturing Supply Chain Performance

Abstract

Achieving net-zero carbon emissions by 2050 is a global commitment shared across industries. This study explores the implementation of Sustainable Lean Management in small and medium-sized enterprises (SMEs) within the metal product manufacturing sector. By employing production value stream mapping, pain point analysis, and the application of seven green waste management principles—augmented by professional coaching, on-site process improvement tools, and quality control circle (QCC) strategies—the study assessed five key performance metrics: delivery rate, operational efficiency, product quality, inventory management, and green value creation, both before and after the interventions.This study presents a comprehensive cradleto-gate carbon footprint (CF) assessment of a representative metal hand tool product, integrating life cycle assessment (LCA) methodologies with Sustainable Lean Management practices in Taiwanese SMEs. Following ISO 14067 and ISO 14044, the analysis covers raw material acquisition, manufacturing, transportation, and packaging. Data Quality Rating (DQR) was applied to ensure robustness, and truncation criteria were set at 1% per process, 5% total. The findings show manufacturing processes, particularly outsourced forging, heat treatment, and electroplating, account for over 90% of emissions. A complementary case study on Sustainable Lean demonstrates that Lean & Green practices not only reduce waste but also enhance operational efficiency, contributing to ESG objectives. The study highlights methodological rigor, industrial implications, and policy recommendations for net-zero transition.