Bridgewater State University book store is a small facility that sells books and supplies. It has one checkout counter where one employee operates the cash register. The combination of the cash register and the operator is the server (or service facility) in this waiting line system; the students who line up at the counter to pay for their selections form the waiting line.
Students arrive at a rate of 24 per hour according to a Poisson distribution (?=24), and service times are exponentially distributed, with a mean rate of 30 customers per hour (µ=30). The bookstore manager is considering hiring an extra employee if there is a big chance of having 5 customers in the queuing system.
As a Service Operations Management expert providing consulting, would you advice hiring that extra employee? Why or why not?
FORMULAS
Probability that no customers are in waiting line Po = (1 – ?/µ)
Probability that n customers are in waiting line Pn = (?/µ)n Po
Multiple Choice:
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A different answer (i.e. not contained in the options)
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They should hire an extra employee because the probability of having 5 customers in the queuing system is high (66%)
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They should not hire an extra employee because the probability of having 5 customers in the queuing system is too low (2.15%)
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They should not hire an extra employee because the probability of having 5 customers in the queuing system is too low (6.6%)
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They should hire an extra employee because the probability of having 5 customers in the queuing system is high (100%)
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They should hire an extra employee because the probability of having 5 customers in the queuing system is considerable (20%)
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They should not hire an extra employee because the probability of having 5 customers in the queuing system is too low (less than 1%)