A motorcycle manufacturer produces the parts for its vehicles in different locations and transports them to its plant for assembly.In order to keep the assembly operations running efficiently,it is vital that all parts be within specification limits.One important part used in the assembly is the engine camshaft,and one important quality characteristic is the case hardness depth.Specifications state that the hardness depth must be between 3.0 mm and 6.0 mm.To investigate the process,the quality control engineer selected 25 daily subgroups of n = 5 and measured the hardness depth.The process yielded a mean of the means $\overline { \overline { x } }$

= 4)50 and an average range = 1.01.Find the sigma level capability of the process.

Question

A motorcycle manufacturer produces the parts for its vehicles in different locations and transports them to its plant for assembly.In order to keep the assembly operations running efficiently,it is vital that all parts be within specification limits.One important part used in the assembly is the engine camshaft,and one important quality characteristic is the case hardness depth.Specifications state that the hardness depth must be between 3.0 mm and 6.0 mm.To investigate the process,the quality control engineer selected 25 daily subgroups of n = 5 and measured the hardness depth.The process yielded a mean of the means

\overline { \overline { x } }

= 4) 50 and an average range = 1.01.Find the sigma level capability of the process.

= 4)50 and an average range = 1.01.Find the sigma level capability of the process.

Quizplus · Accepted Answer

The sigma level capability of the process is calculated as:$$\sigma level capability = \frac{\overline { \overline { x } } - LSL}{6\sigma}$$where:$$\overline { \overline { x } }$$ is the mean of the meansLSL is the lower specification limit$$\sigma$$ is the standard deviationIn this case, we have:$$\overline { \overline { x } } = 4.50 mm$$LSL = 3.0 mm$$\sigma = \frac{R}{d_2} = \frac{1.01}{2.326} = 0.434 mm$$Therefore, the sigma level capability is:$$\sigma level capability = \frac{4.50 - 3.0}{6(0.434)} = 3.45$$So the correct answer is A.

A Motorcycle Manufacturer Produces the Parts for Its Vehicles in Different