Amazon operates a customer call center in Vancouver, which it employs 2 work shifts of 30 employees each. The call center operates 7 days per week. Each work shift lasts 8 hours, and each employee gets paid breaks totaling 1 hour. Breaks are staggered so that the call center is available to customers for the full 8 hours per shift. During a recent week, the first shift had actual operating time of 1,200 hours. Calling records showed that the actual time to complete a call averaged 5.3 minutes, but the expected time per call was 4.5 minutes. During this week, the first shift completed 11,000 calls, of which 1,100 were repeat calls from customers whose problems were not resolved during the first call. Repeat calls are counted as defective calls