Randy needs to decide where to get a haircut. He has narrowed the choice down to two local hair salons – Large Hair Salon (LHS) and Small Hair Cutters (SHC).
A new customer walks into LHS every 15 minutes on average, with a standard deviation of 15 minutes. At SHC, a customer walks in every hour on average, with a standard deviation of 1 hour. LHS has a staff of 4 barbers, while SHC has 1 barber. The average service time at both salons is 30 minutes, with a standard deviation of 30 minutes.
Q1. If Randy walks into SHC, how long, on average, will he wait in line (in minutes) before he receives a haircut? (Only include the waiting time, not any service time)
Q2. SHC provides drinks and chocolate chip cookies to customers that are waiting in line before receiving service. SHC estimates that every minute of customer waiting time costs them 25 cents because of the consumed food. What is the cost of food (in $) SHC spends per day? Assume that SHC operates for 10 hours each day.
Q3. How many customers will there be waiting in line at SHC on average?
Q4. If Randy walks into LHS, how long, on average, will he wait in line (in minutes) before he receives a haircut? (Only include the waiting time, not any service time)
Q5. What is the total average flow time (in minutes) of LHS, which includes both the waiting time and the time in service?
Q6. How many customers, on average will be in LHS, including both customers waiting in line and customers being served?
Q7. What is the average number of customers in service (excluding those that are waiting in line) at LHS?
Q8. What is the average number of customers waiting in line (excluding those that are being served) at LHS?
Q9. LHS will buy out SHC. LHS will then close SHC’s operations and serve all customers, including existing SHC customers, at the LHS location only. Assuming that the previous traffic of SHC customers now flows to the LHS location, what is the new inter-arrival time (in minutes) at LHS? (Hint: Find the new demand by adding the demand for LHS and the demand for SHC. From the new demand, find the new inter-arrival time.)