Question

A delivery process has a target of 5 hours plus or minus one hour. The process standard deviation is estimated as 0.24 hours. The process has a ____ sigma quality level.

Answer 1

the sigma quality level is 8.33

Explanation:

given the data in the question;

Target of a delivery process = 5 hours plus or minus one hour i.e 5 ± 1

standard deviation of the process σ = 0.24 hours.

so,

The Lower Limit
`L_L` of the target will be;

`L_L` = 5 hours - 1 hours = 4 hours

And the Upper Limit
`U_L` of the target will be;

`U_L` = 5 hours + 1 hours = 6 hours

sigma quality level = ?

Now, to get the sigma quality level, we use the following expression;

sigma quality level = ( Upper Limit
`U_L` of the target - Lower Limit
`L_L` of the target ) / standard deviation of the process

sigma quality level = (
`U_L` -
`L_L` ) / σ

so we substitute in our values

sigma quality level = ( 6 - 4 ) / 0.24

sigma quality level = 2 / 0.24

sigma quality level = 8.33

Therefore, the sigma quality level is 8.33