Ch09 Service Opera Ti Ions
Transcript of Ch09 Service Opera Ti Ions
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1 2002 South-Western/Thomson Learning2002 South-Western/Thomson Learning TMTM
Slides preparedSlides prepared
by John Loucksby John Loucks
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Chapter 9Chapter 9Chapter 9Chapter 9
Service OperationsService Operations
Planning and SchedulingPlanning and Scheduling
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OverviewOverviewOverviewOverview
IntroductionIntroduction
Scheduling QuasiScheduling Quasi--Manufacturing Service OperationsManufacturing Service Operations
Scheduling CustomerScheduling Customer--asas--Participant ServiceParticipant Service
OperationsOperations Scheduling CustomerScheduling Customer--asas--Product Service OperationsProduct Service Operations
WrapWrap--Up: What WorldUp: What World--Class Companies DoClass Companies Do
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IntroductionIntroductionIntroductionIntroduction
ServicesServices are operations with:are operations with:
Intangible outputs that ordinarily cannot beIntangible outputs that ordinarily cannot be
inventoriedinventoried
Close customer contactClose customer contact Short lead timesShort lead times
High labor costs relative to capital costsHigh labor costs relative to capital costs
Subjectively determined qualitySubjectively determined quality
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IntroductionIntroductionIntroductionIntroduction
Facts about service businesses:Facts about service businesses:
Enormous diversityEnormous diversity
Service businesses can be any sizeService businesses can be any size
Twice as many nonTwice as many non--retail service businesses asretail service businesses asretailretail
Technical training important due to significantTechnical training important due to significant
dependence on computers, automation anddependence on computers, automation and
technologytechnology
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IntroductionIntroductionIntroductionIntroduction
OtherFacts about service businesses:OtherFacts about service businesses:
Service workers well paid relative toService workers well paid relative to
manufacturingmanufacturing
Need better planning, controlling, andNeed better planning, controlling, andmanagement to stay competitivemanagement to stay competitive
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Some of the Largest Service BusinessesSome of the Largest Service BusinessesSome of the Largest Service BusinessesSome of the Largest Service Businesses
Rank in the top 20 US Corporations:Rank in the top 20 US Corporations:
AT&TAT&T
WalWal--MartMart
CitigroupCitigroup State FarmState Farm
SBC CommunicationsSBC Communications
Sear,R
oebuck & CompanySear,R
oebuck & Company
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Spectrum of Service IndustriesSpectrum of Service IndustriesSpectrum of Service IndustriesSpectrum of Service Industries
TransportationTransportation BankingBanking
RetailingRetailing
Health CareHealth Care
EntertainmentEntertainment
InsuranceInsurance Real EstateReal Estate
CommunicationsCommunications
UtilitiesUtilities
and more and more
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No Clear Line BetweenNo Clear Line Between
Manufacturing and Service FirmsManufacturing and Service Firms
No Clear Line BetweenNo Clear Line Between
Manufacturing and Service FirmsManufacturing and Service Firms
EveryEvery business, whether manufacturing or service,business, whether manufacturing or service,
has a mix of customer service aspects and productionhas a mix of customer service aspects and production
aspects in its operationsaspects in its operations
Manufacturing has much to learn from services thatManufacturing has much to learn from services thatexcelexcel
Services have much to learn from manufacturers thatServices have much to learn from manufacturers that
excelexcel
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Manufacturing and Service JobsManufacturing and Service JobsManufacturing and Service JobsManufacturing and Service Jobs
Percentage of US JobsPercentage of US Jobs
19881988 19981998 2008*2008*
Manufacturing JobsManufacturing Jobs 16.1%16.1% 13.4%13.4% 11.6%11.6%
Service JobsService Jobs 66.266.2 70.870.8 73.973.9
* Projected* Projected
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Operations StrategiesOperations StrategiesOperations StrategiesOperations Strategies
Positioning strategiesPositioning strategies contain two elements:contain two elements:
Type of service designType of service design
Standard or customStandard or custom
Amount of customer contactAmount of customer contact Mix of physical goods and intangible servicesMix of physical goods and intangible services
Type of production processType of production process
QuasiQuasi--manufacturingmanufacturing
CustomerCustomer--asas--participantparticipant
CustomerCustomer--asas--productproduct
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Types of Service OperationsTypes of Service OperationsTypes of Service OperationsTypes of Service Operations
QuasiQuasi--manufacturingmanufacturing
Production occurs much as manufacturingProduction occurs much as manufacturing
Physical goods dominant over intangible servicesPhysical goods dominant over intangible services
CustomerCustomer--asas--participantparticipant High degree of customer involvementHigh degree of customer involvement
Physical goods may or may not be significantPhysical goods may or may not be significant
Service either standard or customService either standard or custom
CustomerCustomer--asas--productproduct
Service performed on customer... usually customService performed on customer... usually custom
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Scheduling Challenges in ServicesScheduling Challenges in ServicesScheduling Challenges in ServicesScheduling Challenges in Services
Planning and controlling dayPlanning and controlling day--toto--day activitiesday activities
difficult due to:difficult due to:
Services produced and delivered by peopleServices produced and delivered by people
Pattern of demand for services is nonPattern of demand for services is non--uniformuniform
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NonNon--Uniform DemandUniform DemandNonNon--Uniform DemandUniform Demand
Cannot inventory services in advance of highCannot inventory services in advance of high--demanddemand
periods, so businesses use following tactics:periods, so businesses use following tactics:
Preemptive actions to make demand more uniformPreemptive actions to make demand more uniform
OffOff--peak incentives/discounts (telephone)peak incentives/discounts (telephone) Appointment schedules (dentist)Appointment schedules (dentist)
Fixed schedules (airline)Fixed schedules (airline)
Make operations more flexible so it is easier toMake operations more flexible so it is easier to
vary capacityvary capacity PartPart--time personnel (supermarket)time personnel (supermarket) Subcontractors (postal service)Subcontractors (postal service) InIn--house standby resources (fire department)house standby resources (fire department)
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NonNon--Uniform DemandUniform DemandNonNon--Uniform DemandUniform Demand
Additional tactics used by businesses:Additional tactics used by businesses:
Anticipate demand and schedule employees duringAnticipate demand and schedule employees during
each time period to meet demandeach time period to meet demand
Allow waiting lines to formAllow waiting lines to form These two tactics will be covered in greater detailThese two tactics will be covered in greater detail
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Scheduling QuasiScheduling Quasi--Manufacturing ServicesManufacturing ServicesScheduling QuasiScheduling Quasi--Manufacturing ServicesManufacturing Services
ProductProduct--Focused OperationsFocused Operations
Resemble productResemble product--focused production linesfocused production lines
Customer demand is forecast and capacityCustomer demand is forecast and capacity
decisions made just as in manufacturingdecisions made just as in manufacturing High volumes of standardized productsHigh volumes of standardized products
Management focused on controlling productionManagement focused on controlling production
costs, product quality, and delivery of physicalcosts, product quality, and delivery of physical
goodsgoods
Example... McDonalds backExample... McDonalds back--room operationroom operation
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Scheduling QuasiScheduling Quasi--Manufacturing ServicesManufacturing ServicesScheduling QuasiScheduling Quasi--Manufacturing ServicesManufacturing Services
ProcessProcess--Focused OperationsFocused Operations
Managed like job shops in manufacturingManaged like job shops in manufacturing
InputInput--output control important to balance capacityoutput control important to balance capacity
between operationsbetween operations Gantt charts used to coordinate flows betweenGantt charts used to coordinate flows between
departmentsdepartments
Sequence of jobs consider sequencing rules,Sequence of jobs consider sequencing rules,
changeover costs, and flow timeschangeover costs, and flow times
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Work Shift SchedulingWork Shift SchedulingWork Shift SchedulingWork Shift Scheduling
Three difficulties in scheduling services:Three difficulties in scheduling services:
Demand variabilityDemand variability
Service time variabilityService time variability
Availability of personnel when neededAvailability of personnel when needed Managers use two tactics:Managers use two tactics:
Use fullUse full--time employees exclusivelytime employees exclusively
Use some fullUse some full--time employees as base and fill intime employees as base and fill inpeak demand with partpeak demand with part--time employeestime employees
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Example: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling Employees
The owner of a haircutting shop wants to convertThe owner of a haircutting shop wants to convertfrom a dropfrom a drop--in system of customer arrivals to anin system of customer arrivals to anappointment system.appointment system.
Each customer requires an average of 30 minutesEach customer requires an average of 30 minutes
of a stylists time. The stylists are all fullof a stylists time. The stylists are all full--timetimeemployees and can work any 4 consecutive days peremployees and can work any 4 consecutive days perweek from 10 a.m. to 7 p.m. (with an hour off forweek from 10 a.m. to 7 p.m. (with an hour off forlunch), Monday through Saturday.lunch), Monday through Saturday.
On the next slide are: 1) average number of dropOn the next slide are: 1) average number of drop--in customers each day, and 2) estimated number ofin customers each day, and 2) estimated number ofcustomer appointments each day.customer appointments each day.
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Example: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling Employees
Mon.Mon. Tue.Tue. Wed.Wed. Thu.Thu. Fri.Fri. Sat.Sat. TotalTotal
DropDrop--insins 4040 3030 1010 2020 3030 6060 190190
AppointmentsAppointments 3232 3232 3232 3232 3232 3232 192192
a) How many stylists are required to service 32a) How many stylists are required to service 32appointments in a day?appointments in a day?
b) What is the minimum number of stylists required perb) What is the minimum number of stylists required per
week?week?c) Use the work shift heuristic procedure to develop thec) Use the work shift heuristic procedure to develop the
stylists weekly work shift schedules.stylists weekly work shift schedules.
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Example: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling Employees
Number of Stylists Required per DayNumber of Stylists Required per Day
Number of customers per dayNumber of customers per day
Number of work hours Number of customers Number of work hours Number of customers
per day per stylistper day per stylist served per hour per stylistserved per hour per stylist
= 32/((8)(2)) = 2 stylists= 32/((8)(2)) = 2 stylists
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Example: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling Employees
Minimum Number of Stylists Required per Week?Minimum Number of Stylists Required per Week?
Number of Customers per WeekNumber of Customers per Week
Number of Customers per Stylist per WeekNumber of Customers per Stylist per Week
= 192/((8 hr/day)(4 days/week)(2 cust./hr/stylist))= 192/((8 hr/day)(4 days/week)(2 cust./hr/stylist))
= 192/64 = 3 stylists= 192/64 = 3 stylists
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Example: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling EmployeesExample: Scheduling Employees
Stylists Weekly Work Shift SchedulesStylists Weekly Work Shift Schedules
StylistStylist Mon.Mon. Tue.Tue. Wed.Wed. Thu.Thu. Fri.Fri. Sat.Sat.
11 22 22 22 22 22 2222 22 22 11 11 11 11
33 11 11 11 11 00 00
Note: Pair of days boxed represent days off.Note: Pair of days boxed represent days off.
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Scheduling CustomerScheduling Customer--asas--Participant ServicesParticipant ServicesScheduling CustomerScheduling Customer--asas--Participant ServicesParticipant Services
Must provide customer ease of use/access features....Must provide customer ease of use/access features....lighting, walkways, etc.lighting, walkways, etc.
Layouts must focus on merchandising and attractiveLayouts must focus on merchandising and attractive
display of productsdisplay of products
Employee performance crucial to customerEmployee performance crucial to customer
satisfactionsatisfaction
Waiting lines used extensively to level demandWaiting lines used extensively to level demand
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Waiting Lines in Service OperationsWaiting Lines in Service OperationsWaiting Lines in Service OperationsWaiting Lines in Service Operations
Waiting lines form because:Waiting lines form because:
Demand patterns are irregular or random.Demand patterns are irregular or random.
Service times vary among customers.Service times vary among customers.
Managers try to strike a balance betweenManagers try to strike a balance betweenefficiently utilizing resources and keepingefficiently utilizing resources and keeping
customer satisfaction high.customer satisfaction high.
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Waiting Line ExamplesWaiting Line ExamplesWaiting Line ExamplesWaiting Line Examples
Computer printing jobs waiting for printingComputer printing jobs waiting for printing
Workers waiting to punch a time clockWorkers waiting to punch a time clock
Customers in line at a driveCustomers in line at a drive--up windowup window
Drivers waiting to pay a highway tollDrivers waiting to pay a highway toll Skiers waiting for a chair liftSkiers waiting for a chair lift
Airplanes waiting to take offAirplanes waiting to take off
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Waiting Line AnalysisWaiting Line AnalysisWaiting Line AnalysisWaiting Line Analysis
Assists managers in determining:Assists managers in determining:
How many servers to useHow many servers to use
Likelihood a customer will have to waitLikelihood a customer will have to wait
Average time a customer will waitAverage time a customer will wait Average number of customers waitingAverage number of customers waiting
Waiting line space neededWaiting line space needed
Percentage of time all servers are idlePercentage of time all servers are idle
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Waiting Line TerminologyWaiting Line TerminologyWaiting Line TerminologyWaiting Line Terminology
QueueQueue -- a waiting linea waiting line
ChannelsChannels -- number of waiting lines in a queuingnumber of waiting lines in a queuing
systemsystem
Service phasesService phases number of steps in service processnumber of steps in service process Arrival rateArrival rate ((PP)) -- rate at which persons or thingsrate at which persons or things
arrive (in arrivals per unit of time)arrive (in arrivals per unit of time)
Service rateService rate ((QQ)) -- rate that arrivals are serviced (inrate that arrivals are serviced (in
arrivals per unit of time)arrivals per unit of time)
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Waiting Line TerminologyWaiting Line TerminologyWaiting Line TerminologyWaiting Line Terminology
Queue disciplineQueue discipline -- rule that determines the order inrule that determines the order inwhich arrivals are servicedwhich arrivals are serviced
Queue lengthQueue length number of arrivals waiting for servicenumber of arrivals waiting for service
Time in systemTime in system an arrivals waiting timean arrivals waiting time andandservice timeservice time
UtilizationUtilization degree to which any part of the servicedegree to which any part of the service
system is occupied by an arrivalsystem is occupied by an arrival
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Queuing System StructuresQueuing System StructuresQueuing System StructuresQueuing System Structures
Single PhaseSingle Phase -- Single ChannelSingle Channel
Single PhaseSingle Phase -- MultichannelMultichannel
SS11
SS11
SS22
SS33
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Queuing System StructuresQueuing System StructuresQueuing System StructuresQueuing System Structures
MultiphaseMultiphase -- Single ChannelSingle Channel
MultiphaseMultiphase -- MultichannelMultichannel
SS1212SS1111
SS1212SS1111
SS2222
SS2121
SS3232SS3131
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Definitions of Queuing System VariablesDefinitions of Queuing System VariablesDefinitions of Queuing System VariablesDefinitions of Queuing System Variables
PP = average arrival rate= average arrival rate
1/1/PP = average time between arrivals= average time between arrivals
= average service rate for each server= average service rate for each server
1/1/ = average service time= average service timenn11 = average number of arrivals waiting= average number of arrivals waiting
nnSS = average number of arrivals in the system= average number of arrivals in the system
tt11
= average time arrivals wait= average time arrivals wait
ttSS = average time arrivals are in the system= average time arrivals are in the system
PPnn
= probability of exactly= probability of exactly nn arrivals in the systemarrivals in the system
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Model 1Model 1
Single channelSingle channel
Single phaseSingle phase
Poisson arrivalPoisson arrival--rate distributionrate distribution Poisson servicePoisson service--rate distributionrate distribution
Unlimited maximum queue lengthUnlimited maximum queue length
Examples:Examples:
SingleSingle--booth theatre ticket salesbooth theatre ticket sales SingleSingle--scanner airport security stationscanner airport security station
Queuing ModelsQueuing ModelsQueuing ModelsQueuing Models
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Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1
Jim Beam pulls stock from his warehouse shelvesJim Beam pulls stock from his warehouse shelvesto fill customer orders. Customer orders arrive at ato fill customer orders. Customer orders arrive at a
mean rate of 20 per hour. The arrival rate is Poissonmean rate of 20 per hour. The arrival rate is Poisson
distributed. Each order received by Jim requires andistributed. Each order received by Jim requires an
average of two minutes to pull. The service rate isaverage of two minutes to pull. The service rate isPoisson distributed also.Poisson distributed also.
Questions to follow Questions to follow
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Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1
Service Rate DistributionService Rate Distribution
QuestionQuestion
What is Jims mean service rate per hour?What is Jims mean service rate per hour?
AnswerAnswerSince Jim can process an order in an average timeSince Jim can process an order in an average time
of 2 minutes (= 2/60 hr.), then the mean serviceof 2 minutes (= 2/60 hr.), then the mean service
rate, , equals 1/(mean service time), or60/2 =rate, , equals 1/(mean service time), or60/2 =
30/hr.30/hr.
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Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1
Average Time in the SystemAverage Time in the System
QuestionQuestion
What is the average time an order must wait fromWhat is the average time an order must wait fromthe time Jim receives the order until it is finishedthe time Jim receives the order until it is finishedbeing processed (i.e. its turnaround time)?being processed (i.e. its turnaround time)?
AnswerAnswer
WithWith PP = 20 per hour and= 20 per hour and QQ = 30 per hour, the= 30 per hour, the
average time an order waits in the system is:average time an order waits in the system is:ttSS = 1/(= 1/( -- PP ) = 1/(30) = 1/(30 -- 20)20)
= 1/10 hour or 6 minutes= 1/10 hour or 6 minutes
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Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1
Average Length of QueueAverage Length of Queue
QuestionQuestion
What is the average number of orders Jim hasWhat is the average number of orders Jim haswaiting to be processed?waiting to be processed?
AnswerAnswer
The average number of orders waiting in theThe average number of orders waiting in thequeue is: nqueue is: n11 == PP
22/[(/[( -- PP)])]
= (20)= (20)22
/[(30)(30/[(30)(30--20)]20)]= 400/300= 400/300
= 4/3 or 1.33 orders= 4/3 or 1.33 orders
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Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1Example: Queuing Model 1
Utilization FactorUtilization Factor
QuestionQuestion
What percentage of the time is Jim processingWhat percentage of the time is Jim processingorders?orders?
AnswerAnswer
The percentage of time Jim is processing orders isThe percentage of time Jim is processing orders isequivalent to the utilization factor,equivalent to the utilization factor, PP//QQ. Thus, the. Thus, the
percentage of time he is processing orders is:percentage of time he is processing orders is:PP//QQ = 20/30= 20/30
= 2/3 or 66.67%= 2/3 or 66.67%
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Queuing ModelsQueuing ModelsQueuing ModelsQueuing Models
Model 2Model 2 Single channelSingle channel
Single phaseSingle phase
Poisson arrivalPoisson arrival--rate distributionrate distribution
Constant service rateConstant service rate
Unlimited maximum queue lengthUnlimited maximum queue length
Examples:Examples:
SingleSingle--booth automatic car washbooth automatic car wash Coffee vending machineCoffee vending machine
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Example: Queuing Model 2Example: Queuing Model 2Example: Queuing Model 2Example: Queuing Model 2
The mechanical pony ride machine at theThe mechanical pony ride machine at theentrance to a very popular Jentrance to a very popular J--Mart store provides 2Mart store provides 2minutes of riding for $.50. Children (accompanied ofminutes of riding for $.50. Children (accompanied ofcourse!) wanting to ride the pony arrive according tocourse!) wanting to ride the pony arrive according to
a Poisson distribution with a mean rate of 15 pera Poisson distribution with a mean rate of 15 perhour.hour.
a) What fraction of the time is the pony idle?a) What fraction of the time is the pony idle?
b) What is the average number of children waiting tob) What is the average number of children waiting to
ride the pony?ride the pony?c) What is the average time a child waits for a ride?c) What is the average time a child waits for a ride?
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Example: Queuing Model 2Example: Queuing Model 2Example: Queuing Model 2Example: Queuing Model 2
Fraction of Time Pony is IdleFraction of Time Pony is Idle
PP = 15 per hour= 15 per hour
QQ = 60/2 = 30 per hour= 60/2 = 30 per hour
Utilization =Utilization = PP//QQ = 15/30 = .5= 15/30 = .5
Idle fraction = 1Idle fraction = 1 Utilization = 1Utilization = 1 -- .5 = .5.5 = .5
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Example: Queuing Model 2Example: Queuing Model 2Example: Queuing Model 2Example: Queuing Model 2
Average Number of children Waiting for a RideAverage Number of children Waiting for a Ride
Average Time a Child Waits for a RideAverage Time a Child Waits for a Ride
or 1 minuteor 1 minute
1
15n . 5 children
15!
1
15t = = .01667 hours
2(-) 2(30)(30 - 15)!
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Queuing ModelsQueuing ModelsQueuing ModelsQueuing Models
Model 3Model 3 Single channelSingle channel
Single phaseSingle phase
Poisson arrivalPoisson arrival--rate distributionrate distribution
Poisson servicePoisson service--rate distributionrate distribution
Limited maximum queue lengthLimited maximum queue length
Examples:Examples:
Auto repair shop with limited parking spaceAuto repair shop with limited parking space Bank driveBank drive--thru with limited waiting lanethru with limited waiting lane
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Queuing ModelsQueuing ModelsQueuing ModelsQueuing Models
Model 4Model 4 Multiple channelMultiple channel
Single phaseSingle phase
Poisson arrivalPoisson arrival--rate distributionrate distribution
Poisson servicePoisson service--rate distributionrate distribution
Unlimited maximum queue lengthUnlimited maximum queue length
Examples:Examples:
Expressway exit with multiple toll boothsExpressway exit with multiple toll booths Bank with multiple teller stationsBank with multiple teller stations
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Scheduling CustomerScheduling Customer--asas--Product ServicesProduct ServicesScheduling CustomerScheduling Customer--asas--Product ServicesProduct Services
Wide range of complexityWide range of complexity
Every facet designed around the customerEvery facet designed around the customer
Highly trained, motivated, and effective workforceHighly trained, motivated, and effective workforce
critical to successcritical to success WaitingWaiting--line analysis can be helpful in determiningline analysis can be helpful in determining
staffing levelsstaffing levels
In more complex operations, simulation is a helpfulIn more complex operations, simulation is a helpful
tool in scheduling resourcestool in scheduling resources
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Reasons for Simulating OperationsReasons for Simulating OperationsReasons for Simulating OperationsReasons for Simulating Operations
Experimentation with the real system is impossible,Experimentation with the real system is impossible,impractical, or uneconomical.impractical, or uneconomical.
System is so complex that mathematical formulasSystem is so complex that mathematical formulas
cannot be developed.cannot be developed.
Values of the systems variables are not known withValues of the systems variables are not known with
certainty.certainty.
Problem under consideration involves the passage ofProblem under consideration involves the passage of
time and simulation could be fastertime and simulation could be faster
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Procedures of Computer SimulationProcedures of Computer SimulationProcedures of Computer SimulationProcedures of Computer Simulation
Define the problem.Define the problem. Develop and computerDevelop and computer--program a model of problem.program a model of problem.
Identify the variables and parameters.Identify the variables and parameters.
Specify the decision rules.Specify the decision rules.
Gather data and specify variables and parameters.Gather data and specify variables and parameters.
Specify timeSpecify time--incrementing procedures.incrementing procedures.
Specify summarizing procedures.Specify summarizing procedures.
Process the simulation.Process the simulation. Evaluate the results of the simulation.Evaluate the results of the simulation.
Recommend a course of action.Recommend a course of action.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Whenever an international plane arrives atWhenever an international plane arrives atLincoln airport the two customs inspectors on dutyLincoln airport the two customs inspectors on duty
set up operations to process the passengers.set up operations to process the passengers.
Incoming passengers must first have theirIncoming passengers must first have their
passports and visas checked. This is handled by onepassports and visas checked. This is handled by one
inspector. The time required to check a passenger'sinspector. The time required to check a passenger's
passports and visas can be described by thepassports and visas can be described by the
probability distribution on the next slide.probability distribution on the next slide.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Time Required toTime Required to
Check a Passenger'sCheck a Passenger's
Passport and VisaPassport and Visa ProbabilityProbability
20 seconds20 seconds.20
.20
40 seconds40 seconds .40.40
60 seconds60 seconds .30.30
80 seconds80 seconds .10.10
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
After having their passports and visas checked,After having their passports and visas checked,the passengers next proceed to the second customsthe passengers next proceed to the second customs
official who does baggage inspections. Passengersofficial who does baggage inspections. Passengers
form a single waiting line with the official inspectingform a single waiting line with the official inspecting
baggage on a first come, first served basis.baggage on a first come, first served basis.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
The time required for baggage inspection has theThe time required for baggage inspection has thefollowing probability distribution:following probability distribution:
Time Required ForTime Required For
Baggage InspectionBaggage Inspection ProbabilityProbability
No Time .25No Time .25
1 minute .601 minute .60
2 minutes .102 minutes .10
3 minutes .053 minutes .05
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Random Number MappingRandom Number Mapping
Time Required toTime Required to
Check a Passenger's RandomCheck a Passenger's Random
Passport and VisaPassport and Visa ProbabilityProbability NumbersNumbers
20 seconds .20 0020 seconds .20 00 -- 1919
40 seconds .40 2040 seconds .40 20 -- 5959
60 seconds .30 6060 seconds .30 60 -- 8989
80 seconds .1080 seconds .10 9090 -- 9999
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Random Number MappingRandom Number Mapping
Time Required For RandomTime Required For Random
Baggage InspectionBaggage Inspection ProbabilityProbability NumbersNumbers
No Time .25 00No Time .25 00 -- 24241 minute .60 251 minute .60 25 -- 8484
2 minutes .10 852 minutes .10 85 -- 9494
3 minutes .05 953 minutes .05 95 -- 9999
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
NextNext--Event Simulation RecordsEvent Simulation Records
For each passenger the following information must beFor each passenger the following information must be
recorded:recorded:
When his service begins at the passport controlWhen his service begins at the passport controlinspectioninspection
The length of time for this serviceThe length of time for this service
When his service begins at the baggage inspectionWhen his service begins at the baggage inspection
The length of time for this serviceThe length of time for this service
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Time RelationshipsTime Relationships
Time a passenger begins serviceTime a passenger begins service
by the passport inspectorby the passport inspector
= (Time the previous passenger= (Time the previous passengerstarted passport service)started passport service)
+ (Time of previous passenger's+ (Time of previous passenger's
passport service)passport service)
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Time RelationshipsTime Relationships
Time a passenger begins serviceTime a passenger begins service
by the baggage inspectorby the baggage inspector
(If passenger does not wait for baggage inspection)(If passenger does not wait for baggage inspection)= (Time passenger completes service= (Time passenger completes service
with the passport control inspector)with the passport control inspector)
(If the passenger does wait for baggage inspection)(If the passenger does wait for baggage inspection)
= (Time previous passenger completes= (Time previous passenger completes
service with the baggage inspector)service with the baggage inspector)
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Time RelationshipsTime RelationshipsTime a customer completes serviceTime a customer completes service
at the baggage inspectorat the baggage inspector
= (Time customer begins service with= (Time customer begins service withbaggage inspector)baggage inspector)
+ (Time required for baggage inspection)+ (Time required for baggage inspection)
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
A chartered plane from abroad lands at LincolnA chartered plane from abroad lands at LincolnAirport with 80 passengers. Simulate the processingAirport with 80 passengers. Simulate the processing
of the first 10 passengers through customs.of the first 10 passengers through customs.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Simulation Worksheet (partial)Simulation Worksheet (partial)
Passport ControlPassport Control Baggage InspectionsBaggage Inspections
Pass. Time Ran. Serv. Time Time Ran. Serv. TimePass. Time Ran. Serv. Time Time Ran. Serv. Time
Num.
Beg.
Num.
Time End Beg.
Num.
Time EndNum.
Beg.
Num.
Time End Beg.
Num.
Time End1 0:00 93 1:20 1:20 1:20 13 0:00 1:201 0:00 93 1:20 1:20 1:20 13 0:00 1:20
2 1:20 63 1:00 2:20 2:20 08 0:00 2:202 1:20 63 1:00 2:20 2:20 08 0:00 2:20
3 2:20 26 :40 3:00 3:00 60 1:00 4:003 2:20 26 :40 3:00 3:00 60 1:00 4:00
43:00 1
6:20 3:20
4:00 13 0:00
4:00
43:00 1
6:20 3:20
4:00 13 0:00
4:00
5 3:20 21 :40 4:00 4:00 68 1:00 5:005 3:20 21 :40 4:00 4:00 68 1:00 5:00
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
Simulation Worksheet (continued)Simulation Worksheet (continued)
Passport ControlPassport Control Baggage InspectionsBaggage Inspections
Pass. Time Ran. Serv. Time Time Ran. Serv. TimePass. Time Ran. Serv. Time Time Ran. Serv. Time
Num.
Beg.
Num.
Time End Beg.
Num.
Time EndNum.
Beg.
Num.
Time End Beg.
Num.
Time End6 4:00 26 :40 4:40 5:00 40 1:00 6:006 4:00 26 :40 4:40 5:00 40 1:00 6:00
7 4:40 70 1:00 5:40 6:00 40 1:00 7:007 4:40 70 1:00 5:40 6:00 40 1:00 7:00
8 5:40 55 :40 6:20 7:00 27 1:00 8:008 5:40 55 :40 6:20 7:00 27 1:00 8:00
9 6:20 72 1:00 7:20 8:00 23 0:00 8:009 6:20 72 1:00 7:20 8:00 23 0:00 8:00
10 7:20 89 1:00 8:20 8:20 64 1:00 9:2010 7:20 89 1:00 8:20 8:20 64 1:00 9:20
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
ExplanationExplanationFor example, passenger 1 begins being served byFor example, passenger 1 begins being served by
the passport control inspector immediately. Histhe passport control inspector immediately. His
service time is 1:20 (80 seconds) at which time heservice time is 1:20 (80 seconds) at which time he
goes immediately to the baggage inspector whogoes immediately to the baggage inspector who
waves him through without inspection.waves him through without inspection.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
ExplanationExplanationPassenger 2 begins service with passportPassenger 2 begins service with passport
inspector 1:20 minutes (80 seconds) after arrivinginspector 1:20 minutes (80 seconds) after arriving
there (as this is when passenger 1 is finished) andthere (as this is when passenger 1 is finished) and
requires 1:00 minute (60 seconds) for passportrequires 1:00 minute (60 seconds) for passportinspection. He is waved through baggage inspectioninspection. He is waved through baggage inspection
as well.as well.
This process continues in this manner.This process continues in this manner.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
QuestionQuestionHow long will it take for the first 10 passengersHow long will it take for the first 10 passengers
to clear customs?to clear customs?
AnswerAnswer
Passenger 10 clears customs after9 minutes andPassenger 10 clears customs after9 minutes and
20 seconds.20 seconds.
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
QuestionQuestionWhat is the average length of time a customerWhat is the average length of time a customer
waits before having his bags inspected after he clearswaits before having his bags inspected after he clears
passport control? How is this estimate biased?passport control? How is this estimate biased?
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Simulation ExampleSimulation ExampleSimulation ExampleSimulation Example
AnswerAnswerFor each passenger calculate his waiting time:For each passenger calculate his waiting time:
(Baggage Inspection Begins)(Baggage Inspection Begins) -- (Passport Control(Passport Control
Ends)Ends) =0+0+0+40+0+20+20+40+40+0 = 120=0+0+0+40+0+20+20+40+40+0 = 120
seconds.seconds.
120/10 = 12 seconds per passenger.120/10 = 12 seconds per passenger.
This is a biased estimate because we assume thatThis is a biased estimate because we assume that
the simulation began with the system empty. Thus,the simulation began with the system empty. Thus,the results tend to underestimate the average waitingthe results tend to underestimate the average waiting
time.time.
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WrapWrap--Up: WorldUp:World--Class PracticeClass PracticeWrapWrap--Up: WorldUp:World--Class PracticeClass Practice
Successful companies have:Successful companies have: Adapted advanced and wellAdapted advanced and well--known planning,known planning,
analyzing, and controlling approaches firstanalyzing, and controlling approaches firstdeveloped in manufacturingdeveloped in manufacturing
Recognized the unique properties of serviceRecognized the unique properties of serviceoperations and developed novel managementoperations and developed novel managementapproaches for these operationsapproaches for these operations
Classify service operations into three types... quasiClassify service operations into three types... quasi
manufacturing, customermanufacturing, customer--asas--participant, orparticipant, orcustomercustomer--asas--product...provides framework forproduct...provides framework foranalysis.analysis.
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WrapWrap--Up:WorldUp:World--Class PracticeClass PracticeWrapWrap--Up:WorldUp:World--Class PracticeClass Practice
Factors that create satisfied customersFactors that create satisfied customers Extrinsic quality of servicesExtrinsic quality of services
The facilities...comfort, convenience, andThe facilities...comfort, convenience, andatmosphereatmosphere
The chemistry between customer and people inThe chemistry between customer and people inservice system...friendliness and courtesyservice system...friendliness and courtesy
Skill, competence, and professionalism of theSkill, competence, and professionalism of thepersonnelpersonnel
The value of the service; cost relative to theThe value of the service; cost relative to thequantity of services receivedquantity of services received
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End of Chapter 9End of Chapter 9End of Chapter 9End of Chapter 9