In Example 7, suppose that management desired a 95% confidence interval on the estimate of mean cycle time and that the error allowed was = 0.05 hours (3 minutes). Using the same initial data given in Table 5, estimate the required total sample size. Although we cut the error in half, by how much did the required sample size increase? Example 7: Software Made Personal Software Made Personal (SMP) customizes software products for clients in two areas: financial tracking and contact management. They have a customer support call center that handles questions for owners of their software from 8 A.M. to 4 P.M. Eastern Time. When a customer calls they use an automated system to select among the two product lines. Each product line has its own operators, and if an appropriate operator is available then the call is immediately routed to the operator; otherwise, the caller is placed in a hold queue. SMP is hoping to reduce the total number of operators they need by cross-training them so that they can answer calls for any product line. This is expected to increase the time to process a call by about 10%. Before considering reducing operators, however, SMP wants to know what their quality of service would be if they simply cross-train the operators they currently have. Using historical data, incoming calls have been modeled as a nonstationary Poisson arrival process and distributions have been fit for operator time to answer questions. Their quality of service measures are caller response time time from initiating a call until speaking to an operator) and the number of callers on hold. Response-time differences of more than 30 seconds matter. 46.86 Table 5 Data Summary for Fast Chip Simulation by Replication Replication Sample Mean for Replication r 1 2 46.09 3 47.64 4 47.43 5 46.94 6 46.43 7 47.11 8 46.56 9 46.73 10 46.80 46.86 S 0.46 In Example 7, suppose that management desired a 95% confidence interval on the estimate of mean cycle time and that the error allowed was = 0.05 hours (3 minutes). Using the same initial data given in Table 5, estimate the required total sample size. Although we cut the error in half, by how much did the required sample size increase? Example 7: Software Made Personal Software Made Personal (SMP) customizes software products for clients in two areas: financial tracking and contact management. They have a customer support call center that handles questions for owners of their software from 8 A.M. to 4 P.M. Eastern Time. When a customer calls they use an automated system to select among the two product lines. Each product line has its own operators, and if an appropriate operator is available then the call is immediately routed to the operator; otherwise, the caller is placed in a hold queue. SMP is hoping to reduce the total number of operators they need by cross-training them so that they can answer calls for any product line. This is expected to increase the time to process a call by about 10%. Before considering reducing operators, however, SMP wants to know what their quality of service would be if they simply cross-train the operators they currently have. Using historical data, incoming calls have been modeled as a nonstationary Poisson arrival process and distributions have been fit for operator time to answer questions. Their quality of service measures are caller response time time from initiating a call until speaking to an operator) and the number of callers on hold. Response-time differences of more than 30 seconds matter. 46.86 Table 5 Data Summary for Fast Chip Simulation by Replication Replication Sample Mean for Replication r 1 2 46.09 3 47.64 4 47.43 5 46.94 6 46.43 7 47.11 8 46.56 9 46.73 10 46.80 46.86 S 0.46