Five months into their Early Bird pilot, Starbucks found that the average arrival rate at the store had plateaued at 1 customer/1.5 minutes. Concerned about the lack of future growth Starbucks reluctantly decided to accelerate installation plans for a service window to accommodate drive-thru traffic.  Store Management was concerned about the effect on the brand of a customer experience that didn't involve Starbucks's classic cafe setting.  Despite these concerns the installation was authorized and the effect was immediate.  The average arrival rate increased 2% each week with no change in service rate at 60 customers/hr.  However, in granting the food service permits for the drive-thru operation, local health officials stipulated that the store management ensure the line of vehicles not extend into the heavily traveled commuter parkway on which Starbucks was located.  Due to the location of the hastily installed service window, the maximum allowable vehicle queue was 5 cars.

IMPORTANT: Start your week count at 0 (your week at the start should be 0)!

8.   At what week after the start of drive-thru operations will the store's utilization meet or exceed 95%? 

9.  If 85% of the Early Morning store traffic is serviced at the drive-thru window, how many vehicles-on average - are waiting in line at the end of the . . . . (Round your answers to 1 decimal place)

     a)  2nd week of operation (week #2):   

     b)  4th week of operation (week #4): 

10.  What week - if any - will the store violate its traffic permit? 

Starbucks's policy is that all store managers have extensive experience as former baristas.  The store manager is contemplating serving as an additional barista during peak hours, thus doubling the store's service rate.

11.   Assuming she serves as a supplemental barista, what week after the start-up of the drive-thru operations should the store manager assume the store's utilization meets or exceeds 95%? 

12.  If 85% of the Early Morning store traffic is serviced at the drive-thru window, how many vehicles-on average are waiting in line at the end of the

     a)  2nd week of operation (week #2): 

     b)  4th week of operation (week #4):