This study aims to identify critical waste, find the causative factor, and make recommendations for improvements to critical waste that causes poor productivity in the company. To achieve this goal, the Lean Six Sigma, Eliminate, Combinate, Rearrange, and Simplify (ECRS), and Theory of Inventive Problem (called TRIZ) methods will be applied to find non-value-added activities and provide improvement solutions to minimize critical waste. In the define stage, for Value Stream Mapping and identification of critical waste, the measurement stage looks for the DPMO value, Sigma level, and process capability. Then, the analysis stage analyzes the root causes of critical waste using 5whays and the improvement stage applying ECRS, TRIZ, and 5S. The results showed that defect waste was a critical waste (25%), DPMO 13128.75, the company's Sigma level was at 3.7, and the process capability was 1.23. The 5whays results show that: there is no means of transportation to replace employees, no formal quality standard, lack of awareness of health & safety, and immature mortar. The solution for minimaxing waste defects is the need to conduct training and evaluate the implementation of the SOP. Carry out production floor cleaning. Install CCTV in the mixer to avoid re-mixing, making adjustments to the quality standards, requiring Concrete Block transportation equipment with better automation level.

Keywords:

Eliminate, Combinate, Rearrange, and Simplify (ECRS), Lean Six Sigma, Theory of Inventive Problem (TRIZ), Waste, 5S