Developing a hybrid approach for lean six sigma project management: A case application in the reamer manufacturing industry

Lean six sigma (LSS) is a well-structured process improvement methodology aimed at removing wastes and defects to increase the operational efficiency of a process. In this article, the authors were tasked to identify the root causes of the reworks and rejections occurring in the polycrystalline diamond (PCD) reamer line of a tool manufacturing industry and provide solutions and implement methods to overcome the rejections. Therefore, the author constructed a hybrid approach comprising the select, define, measure, map, analyse, improve, control, sustain (SDMMAICS) model to enhance the define, measure, analyse, improve, control (DMAIC) approach. Further, decision-making trial and evaluation laboratory (DEMATEL) was incorporated in the improve phase of the LSS model to ensure effective decision making. The model is backed by a KAIZEN framework to ensure the sustenance of the improvements implemented. This hybrid LSS framework was successfully applied and resulted in an increased sigma level from 3.3 to 4.3, improving the cycle time of PCD reamer production by 12%. The hybrid SDMMAICS-DEMATEL approach used is easy to follow and can be adopted in any LSS project. Moreover, the relevance of the model in a part manufacturing setup has been effectively tested and will serve as a reference for researchers in process improvement studies.