Application of Lean Six Sigma to Develop a High Precision Relative Humidity Control

A relatively inexpensive and highly effective design for high precision chamber was developed but the control theory and optimized parameters were totally different from traditional methodologies. Among all kinds of quality programs, lean six sigma (LSS) is the most famous and widely-used method by manufacturing and service industries. The DMAIC (Define, Measure, Analyze, Improve and Control) methodology was used to figure out the key factors relative to high precision of relative humidity and improve the control parameters to meet the target. At the start, the baseline of Z bench was-0.24 and standard deviation was 1.62659. After lean six sigma project implemented, Z bench was up to 1.89 and standard deviation was down to 0.443986. This paper will address the critical process and analysis method for lean six sigma project, especially those for precise control of relative humidity.