Process of Combined Thinking for Long-Term Sourcing

The purpose of this research is to develop a trustworthy decision-making tool that integrates the thinking process, the concept of six sigma, and lean thinking in a long-term supply chain. Supplier quality was recognized as a supply chain barrier in this study because ecologically friendly materials result in a sustainable supply chain. The purpose of this study is to fill a vacuum in the existing literature by emphasizing the connections between theory of constraints, six sigma, and lean thinking for continuous improvement. This study combines the notion of constraints, six sigma, and lean thinking into one evaluation model. Before selecting the best provider with the least amount of environmental impact, the programme looks at a variety of qualitative and quantitative parameters. Supplier 1 appears to be the best, followed by the others. The sensitivity analysis of the model assumes that “higher is better,” and the model's output identifies the best supplier with the least environmental impact.