An empirical study of how the deployment of lean sigma can reduce its enemies: waste, overburden and defect

Lean thinking focuses on shortening cycle time by eliminating non-value-added activities in every process so that the production can flow efficiently. Six sigma focuses on increasing process capability by eliminating process variation to reduce defects. Both concepts are integrated into Lean Sigma methodology and offered to companies in a form of DMAIC framework to achieve two benefits: quality and speed. In terms of lean implementation, several empirical studies have used the DMAIC framework to emphasis on defining and analysing muda (waste), measuring the level of process cycle efficiency, and making the improvement initiatives to remove waste. This research proposed an additional analysis to the existing DMAIC framework on identifying and evaluating muri (overburden), measuring the muri score, and formulating the improvement plans by identifying less ergonomic work conditions that create overburden activities. The proposed DMAIC framework has been deployed in an Indonesian-footwear manufacturer and the implementation indicated that muri analysis can be aligned with muda analysis to create better process improvement. The research also showed that the proposed framework was able to give significant impacts on reducing the two enemies of lean: muda and muri.