QUALITY IMPROVEMENT USING FACTORIAL DESIGN

Dr. Lim Teow Ek is Associate Professor in Nanyang Technological University, Singapore.

Factorial design is probably the most powerful statistical technique for research into any manufacturing process for the purpose of quality improvement. This article discusses the practical aspects of using a full factorial design for the optimization of heat treatment variables to eliminate wobbling of gears.

Factorial experiments were used to investigate the effects of heat treatment variables on 20, 24, and 28 teeth gears to identify the optimum settings. These settings resulted in significant improvements in flatness and concentricity of the gears which led to significant quality improvement.