# Table 19.14 presents some details on the mean and range of 11 samples drawn from a process during…

Table 19.14 presents some details on the

mean and range of 11 samples drawn from a process during routine sampling and

inspection. The readings are the weight of a certain metal deposited on the

surface of a component used in an electro-mechanical device. The lower and

upper specification limits for the weight of metal to be deposited are 10.7 g

and 13.3 g, respectively. The

standard deviation for the process is found

to be 1.28. Assume the sample size to be four.

(a) Develop relevant control charts for the

process (Hint: Since the standard deviation of the population is known, the

control limits can be directly established, see endnote 3 for details)).

(b) Is the process under control? If not,

explain why and suggest what could be done.

(c) Compute the potential and actual

capabilities for the process. What do you infer from this computation? Do you

have any recommendations to make to the organization?