Abstract
In this paper, the optimization on the generic function of a lipstick manufacturing process is discussed. Traditionally, the quality of lipsticks is measured by objective quality characteristics such as appearance. Sensory tests, which are not recommended in quality engineering, had been used to evaluate such quality characteristics. lt is because these quality characteristics are not stable due to the changes of environ mental conditions such as between lot variability or seasonal variation. When sucs quality problems occur, manufacturing conditions were adjusted from time to time,which is known as fire fighting or "mole beating" in Japanese. Among those objective quality characteristics, the ones such as scratches, color uniformity or breaking during usage are manu facturing related quality. As the generic function, the stress/strain relationship was investigated and the results showed that the relationship has satisfied the Hooke's Law with a good improvement.
