Chapter-05-Slides

SimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide1of68ModelingDetailedOperationsChapter5LastrevisionAugust25,2003SimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide2of68WhatWe’llDo...•Explorelower-levelmodelingconstructs•Model5-1:Automotivemaintenance/repairshopMulti-waydecisions,Sets,Variables,Expressions,Submodels,Duplicatingentities,HoldingentitiesTerminatingvs.steady-statesimulations•Debugging•Model5-2:EnhancedautomotiveshopmodelSetsandResourcelogic,nonstationaryarrivalprocess•Model5-3:An(s,S)inventorysimulationBuiltexclusivelyviaSIMANBlocks,ElementsSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide3of68Model5-1:AnAutomotiveMaintenanceandRepairShop•Newthree-baysuburbansatellitefacility•Appointmentstakenuptothreedaysinadvance•Noappointmentstakenforcurrentday•Numberofcallsperday~Poissonwithmean25calls/day55%ofcallsscheduleappointmentforthenextday30%fortwodaysout15%forthreedaysout•Ifnoappointmentisavailableonthedesiredday,there’sa90%chancethatthecallerwillwanttoscheduleforthefollowingdayOther10%justgoawaySimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide4of68AnAutomotiveRepairandMaintenanceShop(cont’d.)•80%leavevehicleforservice,comebacklaterOther20%waitattheshop•WaitcustomersgivenapproximatewaittimeEstimatedservicetime(BookTime)+Allowance(1hour)•Limitoffivewaitcustomersperday•BookTime~44+90*BETA(2,3)minutes•Actualservicetime~GAMM(BookTime/1.05,1.05)minutes•Maximumof24hours(BookTime)scheduledperday(threebays,eighthourseach)SimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide5of68Costs,Revenues•Capitalandlaborcost=$45/hour/bay40-hourworkweek•Revenuefromcustomer=$78/hour(chargedforBookTime,notactualtime)•Overtimecosts$120/hourMaximumofthreehours/day/bay•Ifservicecan’tbecompletedthatday,vehicleisheldovernightandcustomergetsfreeloanercarLoanercarcoststheshop$35/day•Ifserviceisn’tstartedthatday,customertakescarhomeandreturnsnextday–nocosttoshopSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide6of68SystemPerformance•Dailyprofit•DailyBookTime•Dailyactualservicetime•Dailyovertime•DailynumberofwaitappointmentsnotcompletedontimeSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide7of68NewModelingIssues•ServiceSystem–notmanufacturingButcanusesamemodelingcapabilities•Multiple-waydecisionsAppointmententitiesgotooneoffivewaitqueuesbasedondayofappointmentCapabilityavailableinDecidemodule•SetsGroupsofsimilarobjectsReferencebyacommonsetnameandindexintotheset(subscript)–Canalsobereferencedviatheiroriginalname–ArenasetsareorderedServicebayswillbemodeledasasetofresources–AlsousesetsforentitypicturesandappointmentqueuesDefineviaSetsdatamoduleSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide8of68NewModelingIssues(cont’d.)•VariablesandExpressionsCanbereferencedinmodelbynameCanbeone-ortwo-dimensionalarrays,indexedbyoneortwointegersUser-definedVariables–Storesomenumericalvalue(notaformula)–CanbeinitializedinVariabledatamodule–Canbeused,reassignedduringthesimulationrunbyanyentityUser-definedExpressions–Anamedefinedbyamathematicalexpression–Thisnamecanbereferencedanywhereinthemodel–Canuseconstants,Variables,Attributes,systemstatevariables,valuesfromdistribution–connectedviamathematicaloperationsCanuseExpressionBuildertohelpdefine–DefinedinExpressiondatamodule(AdvancedProcesspanel)SimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide9of68NewModelingIssues(cont’d.)•SubmodelsPartitionsimulationmodelintoseveralsmallersubmodels–Canlinkthemtogether,moremanageablepiecesJustlikeanormalmodelviewwithinasubmodelSubmodelscanalsocontainfurthersubmodels,etc.–hierarchicalstructureSubmodelscanbeexternallyconnectedtoothermodulesorsubmodelsNavigatepanelinProjectBarshowssubmodels,underTop-LevelModelSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide10of68NewModelingIssues(cont’d.)•Duplicatingentities“Cloning”anentityEntitiesoftenusedforcontrolDothisviaSeparatemodule•HoldingentitiesHoldentitiesinaqueueuntil–Asignalissentbyanotherentity–AsystemconditionexistsHoldandSignalmodules(AdvancedProcesspanel)Here,usedtoholdcustomersuntilthedayofscheduledserviceSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide11of68AnimationRequirements•Noentitymovement•Canstilldisplayqueues•AppointmentsNumberTypeBookTimehoursperday•BayresourcesSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide12of68SystemorSimulationType•TerminatingKnownstartingandstoppingconditions–partofmodelTimeframeisknown(andfinite)•Steady-StateInitialconditionsarenotalwayswelldefinedNodefinedstoppingcondition(theoreticallyinfinite)Interestedinsystemresponseoverthelongrun•AutomotiverepairmodelStartingandendingtimesknowneachday–Somevehiclescanbeheldoverfromonedaytothenext–Butwe’llsimulatefor20days(approximatelyaworkingmonth)TreatthesystemasterminatingSimulationwithArena,3rded.Chapter5–ModelingDetailedOperationsSlide13of68ArenaModelingPanels•BasicProcesspanelHighestlevelofmodeling•A