At a large pharmacy, first you wait at the line for giving your order. Most of the time (80% of the time) the pharmacist has your drugs ready in 2 minutes. But 20 percent of the time, the pharmacist needs additional time to prepare the drug, and she spends 8 minutes for your prescription. When you have your drugs, you wait some more at the line for cashier. It takes 1 minute to pay for the drugs. The customer throughput of the pharmacy is 120 people per hour.
i. If the managers of the store want to maintain a stable process, how many cashiers and how many pharmacists should they have on duty on average (assuming that one pharmacist works for the prescription of one customer)?
ii. If they employ just the enough number (the minimum integer) of pharmacists to maintain the stable system, what would be their capacity at the ‘filling the prescription' activity in terms of customers?
iii. Then what would be their capacity utilization at the same activity?