Deployment of Lean Six Sigma framework with environmental considerations in SMEs: a case study

Lean Six Sigma is a potent methodology that uses the statistical tools of Six Sigma to reduce product variability and enhance its quality. Meanwhile, it uses lean techniques to decrease process waste and its negative impact on the environment. Lean Six Sigma initiatives can improve the firm's processes and environmental performance by reducing environmental wastes such as excess raw material consumption and harmful air emissions. This paper proposes a Lean Six Sigma framework while considering SMEs' limited resources and workforce experience to improve their process and environmental performance. The framework simultaneously integrates the DMAIC approach and its statistical tools such as the design of experiments, analysis of variance, and process capability analysis to investigate the product's environmental impact using the lean tools that small enterprises could apply, such as value stream maps and 5S. The framework has been validated in a small-sized candle manufacturing enterprise and successfully implemented. It has led to an improvement in candle sooting by 14.5%, burning lifetime by 12%, and daily candle production by 32.2%; on the other hand, the wax waste decreased by 29.6%.