QUestion: A simulation model of a job shop was developed to investigate different scheduling rules. To validate the model, the scheduling rule currently used was incorporated into the model and the resulting output was compared against observed system behavior. By searching the previous year's database records, it was estimated that the average number of jobs in the shop was 22.5 on a given day. Seven independent repli-cations of the model were run, each of 30 days' duration, with the following results for average number of jobs in the shop:
18.9 22.0 19.4 22.1 19.8 21.9 20.2
(a) Develop and conduct a statistical test to evaluate whether model output is consistent with system behavior. Use the level of significance α = 0.05.
(b) What is the power of this test if a difference of two jobs is viewed as critical? What sample size is needed to guarantee a power of 0.8 or higher? (Use α = 0.05.)