Question

Explain the benefit(s) for on-going monitoring of the process using samples. Wouldn't it be better to just do 100% testing?

Answer 1

(a)

On-going monitoring of the process using sample has the following benefits:

(i) The process need not be stopped. It can continue unless some anomaly is found after the sampling test.

(ii) For destructive tests, sampling is the only possibility of testing.

(iii) Adopting proper statistical techniques, it is possible to predict the possible defects of the entire population based on the limited samples.

(iv) In manufacturing processes, control charts are used extensively using on-going monitoring of the process.

(b)

For highly critical components involving human life such as in medical, space or defense systems, 100% testing is to be adopted wherever possible because of the uncertainty of results of sampling. However, it is not at all possible to do 100% testing due to cost, time, facilities needed etc. Also for testing involving destructive testing, 100% testing is impossible because we will be left with no product after the 100%testing in the case of destructive tests,