Eco-Six Sigma: integration of environmental variables into the Six Sigma technique

The impressive results achieved by several companies through the Six Sigma technique have motivated other organisations to follow their footsteps in search for competitiveness. As noticed in the literature, most Six Sigma projects in manufacturing have aimed to obtain process enhancements, focusing mostly on optimising product cycle times with almost none taking into consideration environmental aspects as part of their developments. Furthermore, organisations have been worrying worldwide about environmental issues, seeking to foster their eco-efficiency. As a result, the main objective of this paper is to formally introduce the environmental considerations into the Six Sigma technique by proposing a procedure to incorporate environmental variables into the DMAIC process as a way to increase the eco-efficiency level of the firms. Based on the literature review, a conceptual procedure to incorporate environmental variables into the Six Sigma DMAIC technique is proposed. To verify its possible application to real-life situations an action research was developed and could verify that the traditional Six Sigma approach (dealing only with the manufacturing process variables) was capable of improving the eco-efficiency level of the process area under study by 11%. The consideration of the environmental variables as part of the DMAIC technique as per the proposed approach allowed an additional 20% gain, which demonstrates its adequacy to increase the eco-efficiency level of the manufacturing area under evaluation.