1. a) Explain with example the purpose of using capability index. 2

b) ABC Company manufactures a certain type sophisticated plastic cord of diameter 1 mm for industrial use from the year 2009. At the beginning of operation, the company found a specification of mean 300 PSI with a range of 285 320 PSI for the tensile strength of the cord with 3-sigma level of confidence.

To investigate some complaints related to the tensile strength of the cord, Operations manager analyzed production log and found that average strength and average range of the tensile strength from every batch had been recorded. Every time 5 samples of 6 observations from each batch were taken. He took the last 10 records and documented it as follows.

Sample	Average Strength (PSI)	Avg. Range of strength (PSI)	Sample	Average Strength (PSI)	Avg. Range of strength (PSI)
1	303	4.2	6	302	7.5
2	301	4.5	7	296	8.4
3	296	5.6	8	301	9.1
4	299	6.3	9	300	9.9
5	296	6.8	10	297	10.1

Suppose you are the operations manager; what and how would you analyze it? Show your analysis. What is your recommendation?