Consider a small pharmacy where two pharmacists, one drive-thru assistant and one cashier work.

On average, 50% of the customers come to fill prescriptions, 20% purchase only over the counter (OTC) medication, and 30% for both. Assume that each customer drops one script at a time.

Customers who come in to fill a prescription drop their script with the cashier. This step takes on average 4 minutes per customer.

After spending 6 minutes on a script, the pharmacist realizes that 20% of the scripts are problematic and cannot be filled as is. For those scripts, the pharmacist calls the insurer and/or the doctor's office to resolve the problems. Problem resolution and eventually filling the script takes on average an additional 50 minutes. Assume that all problematic scripts are eventually filled.

The remaining unproblematic scripts take an additional 20 minutes for the pharmacist to fill after the 6-minute review.

All customers pay the cashier. Check-out is on average 5 minutes per customer.

30% of the prescription customers pick up their order at the drive thru. This step is carried out by the drive thru assistant and takes 6 minutes.

a. Compute the capacities of the pharmacists, drive-thru assistant, and the cashier in customers per hour.

Capacity of the pharmacists

b. Seeing that the drive-thru assistant's utilization is so low, the pharmacy decides to merge the cashier and drive-thru positions such that a team of two employees handle the tasks carried out by the cashier and the drive-thru assistant. Does this process redesign affect the overall capacity of the pharmacy? Please justify your answer by using the relevant capacity calculations.