3Lines and Waiting“Every day I get in the queue, that waits for the bus that takes me to you …”Pete Townshend, Magic Bus
4Where the Time Goes In a life time, the average American will spend-- SIX MONTHSWaiting at stoplightsEIGHT MONTHSOpening junk mailONE YEARLooking for misplaced 0bjectsUnsuccessfully returningTWO YEARS phone callsFOUR YEARS Doing houseworkFIVE YEARS Waiting in lineSIX YEARS Eating
5Cultural Attitudes“Americans hate to wait. So business is trying a trick or two to make lines seem shorter…” The New York Times, September 25, 1988“An Englishman, even when he is by himself, will form an orderly queue of one…” George Mikes, “How to be an Alien”“In the Soviet Union, waiting lines were used as a rationing device…” Hedrick Smith, “The Russians”
6Waiting RealitiesInevitability of Waiting: Waiting results from variations in arrival rates and service ratesEconomics of Waiting: High utilization purchased at the price of customer waiting. Make waiting productive (salad bar) or profitable (drinking bar).
7Laws of ServiceMaister’s First Law: Customers compare expectations with perceptions.Maister’s Second Law: Is hard to play catch-up ball.Skinner’s Law: The other line always moves faster.Jenkin’s Corollary: However, when you switch to another other line, the line you left moves faster.
8Remember MeI am the person who goes into a restaurant, sits down, and patiently waits while the wait-staff does everything but take my order.I am the person that waits in line for the clerk to finish chatting with his buddy.I am the one who never comes back and it amuses me to see money spent to get me back.I was there in the first place, all you had to do was show me some courtesy and service The Customer
9Psychology of WaitingThat Old Empty Feeling: Unoccupied time goes slowlyA Foot in the Door: Pre-service waits seem longer that in-service waitsThe Light at the End of the Tunnel: Reduce anxiety with attentionExcuse Me, But I Was First: Social justice with FCFS queue disciplineThey Also Serve, Who Sit and Wait: Avoids idle service capacity
10Approaches to Controlling Customer Waiting Animate: Disneyland distractions, elevator mirror, recorded musicDiscriminate: Avis frequent renter treatment (out of sight)Automate: Use computer scripts to address 75% of questionsObfuscate: Disneyland staged waits (e.g. House of Horrors)
11The Art of Service Recovery “To err is human; to recover, divine” Measure Cost of Lost CustomerListen CarefullyAnticipate Need for RecoveryAct FastTrain EmployeesEmpower the FrontlineInform Customers of Improvement
12Essential Features of Queuing Systems RenegeArrivalprocessQueuedisciplineDepartureCallingpopulationServiceprocessQueueconfigurationBalkNo futureneed forservice
13Arrival Process Arrival process Static Dynamic Random arrivals with constant rateRandom arrivalrate varyingwith timeFacility-controlledCustomer-exercisedcontrolAccept/RejectPriceAppointmentsRenegingBalking
16Poisson and Exponential Equivalence Poisson distribution for number of arrivals per hour (top view)One-hourintervalArrival Arrivals Arrivals Arrival62 min.40 min.123 min.Exponential distribution of time between arrivals in minutes (bottom view)
17Queue Configurations Multiple Queue Single queue Take a Number Enter 3 4286101271195
18Queue Discipline Queue discipline Static (FCFS rule) Dynamic selection based on statusof queueSelection basedon individualcustomerattributesNumber ofcustomerswaitingRound robinPriorityPreemptiveProcessing timeof customers(SPT rule)
20Service Facility Arrangements Service facility Server arrangementParking lot Self-serveCafeteria Servers in seriesToll booths Servers in parallelSupermarket Self-serve, first stage; parallel servers, second stageHospital Many service centers in parallel and series, not all used by each patient
21Topics for DiscussionSuggest some strategies for controlling variability in service times.Suggest diversions that could make waiting less painful.Select a bad and good waiting experience, and contrast the situations with respect to the aesthetics of the surroundings, diversions, people waiting, and attitude of servers.Suggest ways that management can influence the arrival times of customers.What are the benefits of a fast-food employee taking your order while waiting in line?
22Interactive ExerciseThe class breaks into small groups with at least one international student in each group, if possible. Based on overseas travel, each group reports on observations of waiting behavior from a cultural perspective.
24Pronto PizzaDraw a process flow diagram and identify the bottleneck operation.Calculate the expected waiting time in the order preparation queue. Compare this value with your simulation result.Use the ServiceModel computer simulation software and the Pronto.pkg file to determine the number of drivers that minimizes the total cost of salaries and guarantee discounts.
25Pronto Pizza (cont.)Based on your simulation recommended staffing level, what is the probability of paying off on the guarantee?What do you think of this service guarantee policy?What other design or operating suggestions could improve Pronto Pizza’s performance and customer service?