When driving the expected loss generated by the quality deviation, Taguchi (1991b) assumed that an objective characteristic has the uniform distribution in its control limit. But it is reasonable to assume that an objective characteristic has the norm...
When driving the expected loss generated by the quality deviation, Taguchi (1991b) assumed that an objective characteristic has the uniform distribution in its control limit. But it is reasonable to assume that an objective characteristic has the normal distribution than the uniform distribution. Since the triangular distribution is similar to the normal distribution and easy to handle as well, in this article, we first find the optimum measurement interval and the optimum contol limit under the triangular distribution. Under the normal assumption, the modified method is compared to Taguchi`s. Secondly we find the numerical value solution of the optimum measurement interval and the optimum contol limit under the normal distribution.