Meena Company has been producing computer chips with an average life of 290 hours and a standard deviation (s) of 24 hours. The customer specifications are 300 + or - 100 hours for the upper and lower specification limits respectively.
a) Meena has the opportunity to obtain a large order from XYZ Computers if it can produce the computer chips with specification limits of 300 + or - 100 hours. If the minimum acceptable process capability is 1.33 (a 4-sigma process), can Meena meet the customer's specification requirements at this time? If it cannot, explain if it is due to a drifting of the mean or too much variability. Explain.
b) Now suppose that Meena has introduced some changes in its operations. The customer has also agreed to use Meena if Meena can provide a process capability of 1.33 or greater. After the first 20 days of production under the new process, it finds that the average life is 295 hours but it has not determined the standard deviation (s). What is the maximum acceptable value of the standard deviation (σ) for Meena to be selected? The customer's spec limits are still 300 + or - 100 hours.
c) Suppose that Meena is producing computer chips with a σ = 24 hours and it cannot improve on this. Using the process capability index, what are the upper and lower limits for the mean of the process so that Meena can meet the customer requirements at a process capability of 4-sigma limits? Interpret your results.