A theoretical framework to deploy sustainable Lean Six Sigma and its empirical application in manufacturing

Sustainable development drives manufacturing organisations to deploy sustainable improvement approaches. Sustainable Lean Six Sigma (LSS) is an integrated approach that improves the sustainability of a process while increasing product quality. Sustainable LSS deployment necessitates a structured model to systematically and effectively implement Lean, Six Sigma, and sustainability. This study proposes a structured theoretical model that facilitates the seamless integration of these approaches and offers a simplified framework to guide managers in the stepwise implementation of Sustainable LSS. The integration of sustainable LSS is achieved through the theoretical foundation and a framework developed based on a select, define, measure, map, analyse, improve, control, and sustain approach. The proposed framework was tested in select manufacturing organisations to assess its practical applicability in a real environment. By providing managers with a systematic approach and simplified tools and techniques, the framework assists in implementing Sustainable LSS by facilitating the evaluation of projects in manufacturing firms. This study enhances the readiness of manufacturing organisations to embrace Sustainable LSS by providing a comprehensive understanding of the integration model and framework. The systematic implementation process equips researchers and practitioners with the necessary knowledge to apply the Sustainable LSS framework in manufacturing organisations seeking to improve process sustainability.