Green Valley
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CASE STUDY Green Valley
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EXECUTIVE SUMMARY
Green Valley Assembly Company is an establishment that assembles electronic products for manufacturers that require temporary extra production capacity. Green Valley Assembly frequently works under the label of popular manufacturers where high quality is a basic requirement. Recently, Tom Bradley and Sandra Hansen of the Green Valley personnel department have shown interest in implementing a job-enrichment program into the assembly operation. They decided to introduce the program in one wing of the plant and continue with the current method the other wing and after six months, compare the results. After the six month trial period, Tom and Sandra collected data from the two random samples. Each sample (represented by n1 and n2) produced sample means (represented by x1 and x2) and sample standard deviations (represented by s1 and s2) and this would determine whether the consistency of the employees has been affected by the new program. However, there is also concern on whether the job-enrichment program has caused a change in the number of defective products. So they produced another test to determine the whether the job-enrichment program affected the quality of the products.
The analysis includes two tests. The first test conducted was a hypothesis test to determine whether the job-enrichment program changed the average output. The second test performed measured whether the job-enrichment program reduced the proportion of defective products. PHStat was used to calculate t-scores, z-scores and critical values needed in order to determine whether the program would be rejected.
Results from the first hypothesis test determined that the job-enrichment program did not consistently turn out a better average output rate. Results from the second
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CASE STUDY Green Valley
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EXECUTIVE SUMMARY
Green Valley Assembly Company is an establishment that assembles electronic products for manufacturers that require temporary extra production capacity. Green Valley Assembly frequently works under the label of popular manufacturers where high quality is a basic requirement. Recently, Tom Bradley and Sandra Hansen of the Green Valley personnel department have shown interest in implementing a job-enrichment program into the assembly operation. They decided to introduce the program in one wing of the plant and continue with the current method the other wing and after six months, compare the results. After the six month trial period, Tom and Sandra collected data from the two random samples. Each sample (represented by n1 and n2) produced sample means (represented by x1 and x2) and sample standard deviations (represented by s1 and s2) and this would determine whether the consistency of the employees has been affected by the new program. However, there is also concern on whether the job-enrichment program has caused a change in the number of defective products. So they produced another test to determine the whether the job-enrichment program affected the quality of the products.
The analysis includes two tests. The first test conducted was a hypothesis test to determine whether the job-enrichment program changed the average output. The second test performed measured whether the job-enrichment program reduced the proportion of defective products. PHStat was used to calculate t-scores, z-scores and critical values needed in order to determine whether the program would be rejected.
Results from the first hypothesis test determined that the job-enrichment program did not consistently turn out a better average output rate. Results from the second