Answer:
For this process, the capability index is 0.4444
Step-by-step explanation:
Given the data in the question;
Lower specification limit = 22.8 mm
Upper specification limit = 23.2 mm
The standard deviation σ = 0.15 mm
Mean μ = 23
capability index Cpk = ?
Now, Using the formula;
Cpk = min{ [(USL - μ)/3σ], [(μ - LSL)/3σ]
where USL is the Upper specification limit, LSL is the Lower specification limit, σ is the standard deviation, μ is the mean
so we substitute
Cpk = min{ [(23.2 - 23 )/(3×0.15)], [(23 - 22.8)/(3×0.15)] }
Cpk = min{ [0.2 / 0.45 ], [0.2 / 0.45] }
Cpk = min{ [ 0.4444 ], [0.4444] }
Therefore, for this process, the capability index is 0.4444
