cdm operational concept

AIRTRAFFICCONTROLGROUP

CollaborativeDecisionMaking

forOptimisationofNetworkManagement

AnOperationalConceptV1.0

Name Position Signature Date

Prepared AnthonyGunton Manager,ATMInformationServices

[originalsigned]

Endorsed PeterCurran Manager,StrategicOperationalInitiatives

[originalsigned]

Approved JasonHarfield GeneralManager,AirTrafficControlGroup

[originalsigned]

AirservicesAustralia.Allrightsreserved.

ThisdocumentandtheinformationcontainedhereinisthepropertyofAirservicesAustralia.Nopartofthisworkmaybereproducedorcopiedinanyformorbyanymeans(graphic,electronicormechanical,includingphotocopying,recording,tapingorinformationretrievalsystem)orotherwisedisclosedtoanypartyoutsideAirserviceswithoutthepriorconsentoftheGeneralManager,ATCGroup,AirservicesAustralia

CollaborativeDecisionMakingforOptimisationofNetworkManagementAnOperationalConcept

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TableofContentsTableofContents..........................................................................................................................................21. Overview ............................................................................................................................................3

Context .................................................................................................................................................3ThisDocument......................................................................................................................................4

2. UnderstandingNetworkDemand .....................................................................................................52.1 ForecastDemand...........................................................................................................................5

Enroute................................................................................................................................................5Airports.................................................................................................................................................6

2.2 NetworkEffect...............................................................................................................................72.3 OneaMinute.................................................................................................................................7

3. OptimisingNetworkOperations .......................................................................................................84. UserFocusedNetworkManagement................................................................................................95. AirportsTheCriticalNode.............................................................................................................11

Taxiways.............................................................................................................................................12ApronManagement ...........................................................................................................................12

6. CollaborativeDecisionMakinganOperationalConcept.............................................................136.1 Overview......................................................................................................................................136.2 ALayeredApproach ....................................................................................................................146.3 Layer1:DemandandCapacityBalancing....................................................................................17

GatetoGateFlowManagement........................................................................................................17ArrivalOptimisationFlowFocus......................................................................................................18

6.4 Layer2:CapacityOptimisation...................................................................................................19ArrivalOptimisationCapacityFocus................................................................................................19ApronTurnAroundOptimisation .......................................................................................................20DepartureOptimisationCapacityFocus..........................................................................................20IntegratedRunwayManagement ......................................................................................................21

6.5 Layer3:Network(Schedule)Optimisation..................................................................................21AirportTurnaroundOptimisation.......................................................................................................22DepartureOptimisationNetworkFocus ..........................................................................................24Arrival/DepartureOptimisation........................................................................................................25IntegrationofDeparturestoNextAirportArrivals.............................................................................25

Appendix1:CDMExtractfromtheICAOATMOperationalConcept.......................................................................27


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1. Overview1.1 Asairtrafficdemandincreasesanduseofavailablecapacitybecomesmoreproblematic,andasuser and community expectations for flight efficiency, predictability, flexibility and environmentaleffectivenessgrow,themanagementandintegrationofthewholeofnetworkwillbecomeincreasinglycriticaltoeffectiveairtrafficmanagement.1.2 Throughthenext20years,Australianairtrafficdemandisexpectedtoincreaseby70%100%effectivelyadoublingofcurrentdemand,placingstrainonbothairportandterminalareacapacity,andin some cases enroute airspace capacity particularly when disruptive events such as convectiveweatherorfogoccur.1.3 Whilst initiatives areunderway to increase capacity, itwill become increasinglynecessary todevelop capabilities to both balance available capacity against demand, ensuring that the usercommunityhasequitableandconsistentaccesstoallpotentiallyavailablecapacity inthesystemandtofullyutilisenewcapacityasandwhencreated.1.4 Thisbalancingofdemandandcapacityhas traditionallybeen theunilateraldomainof theAirNavigationServiceProvider(ANSP)airtrafficflowmanagementfunction.Throughthenext20yearsthatfunctionwillbeexpandedandaugmentedwitharangeofdistributedcapabilitiesandresponsibilities,and integrated to become the International Civil Aviation Organisation (ICAO) envisaged Global AirTrafficManagement(ATM)OperationalConceptcomponentDemandandCapacityBalancing(DCB).1.5 ForAirservicesAustralia,theexistingcapabilityformanagingthenetworkmustevolvefromitscurrentfocusondemandmanagement,tooneencompassingwholeofbusinesstrajectoryandcrossstakeholder collaborative capacity and network efficiency management utilising CollaborativeDecisionMakingacrossallphasesofflight,fromStrategicPlanningtoTacticalandDynamicOperations.

Context1.6 TheAirTrafficControl (ATC)GroupATM5YearPlan identifies as aprimary serviceoutcome...the optimisation of endtoend ATM system traffic management performance through the continuingdevelopmentanddeploymentofSystemWide InformationManagement, implementationofCollaborativeATM,and costeffectiveoptimisationofdemandagainst system capacity in collaborationwith theoperational servicedomainsandourcustomers1....1.7 Sustaining thatgoal throughthenext1520yearswillpresentsignificantchallenges.As trafficlevels increase, user performance envelops tighten, and currently available latent capacity2 isabsorbed,wholeofnetworkmanagementwillbecomethekeycomponentoftheATMsystemandin1ATCGroupATM5YearPlan20102015,page53,paragraph9.2.12Latentcapacity iscapacity inthesystemthat isavailablewithoutsignificant infrastructureortechnologicalchanges,butwhich iseithernotused,ornotusedeffectively.Itcanbeaccessedbychangestooperationalprocedures,betterforecasting,moreeffectivecoordinationandsoon.


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particular, a key driver in the Performance Based Approach (PBA) to ATM. This has already beenrecognised intheUSNextGeneration(NextGen)programandtheEuropeanSingleEuropeanSkyATMResearch (SESAR) Joint Undertaking and is under active discussion in the Australian ATM StrategicPlanning(ASTRA)process.1.8 This evolution will require the development and implementation of effective data andinformation collection,managementand sharingprocesses,networkoperationsplansand strategies,andcollaborativeplanninganddecisionmakingprocessesthatextendwellbeyondthecurrenttacticaland pretactical timeframes into strategic and very strategic. Itwill also require broadening of thestakeholder engagement level to facilitate sustainable growth in capacity based on a rigorousunderstandingofdemandscenarios.

ThisDocument1.9 Thisoperationalconceptoutlinesarangeofchanges innetworkmanagementthatwillevolvethrough thenext1520 years.Key to the concept is theprincipleof wholeofnetwork informationutilization,managementand interchange,enablingasignificantchange in the rolesofallparticipantswithin the Australian ATM system. This philosophy is underpinned by evolution to a holisticCollaborative Decision Making environment, where the diverging expectations and interests of allmembersoftheATMcommunityarebalancedcooperativelytoachieveabestbusinessoutcomeforallstakeholders.1.10 This document is written to be entirely consistent with the ICAO Global ATM OperationalConcept(GATMOC)visionforfuturedemandandcapacitybalancing,whichenvisages:

DemandandCapacityBalancingwill strategically evaluate systemwide traffic flowsandaerodromecapacities to allow airspace users to determinewhen,where and how they operate,whilemitigatingconflicting needs for airspace and aerodrome capacity. This collaborative process will allow for theefficientmanagement of the air traffic flow through the use of information on systemwide air trafficflows,weatherandassets.Keyconceptualchangesinclude:a. through collaborative decisionmaking at the strategic stage, assetswill be optimized in order to

maximizethroughput,thusprovidingabasisforpredictableallocationandscheduling;b. throughcollaborativedecisionmakingat thepretacticalstage,whenpossible,adjustmentswillbe

madetoassets,resourceallocations,projectedtrajectories,airspaceorganization,andallocationofentry/exittimesforaerodromesandairspacevolumestomitigateanyimbalance;and

c. at the tactical stage, actionswill include dynamic adjustments to the organization of airspace tobalancecapacity,dynamicchangestotheentry/exittimesforaerodromesandairspacevolumes,andadjustmentstotheschedulebytheusers.

1.11 The components discussed in this document do not predispose the need for or use of anyparticular technology (currentlyavailableor indevelopment) theymaybe satisfiedwithproceduralsolutionsbutthroughthemediumandlongtermwillinevitablyrequiretechnicalinnovation.


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2. UnderstandingNetworkDemand2.0.1 As indicated in the ATM 5 Year Plan (201015), the evolution of Air Traffic Services (ATS)throughthenext20yearswillbeinfluencedbyanumberofchallenges.AkeychallengetotheefficientmanagementoftheAustralianairtrafficnetworkwillbetheabilitytoeffectivelycopewith increasingdemandacrossServiceDeliveryEnvironments(SDE)ormoreprecisely,theeffectivemanagementofcapacityagainst thatgrowth indemand.Networkmanagementwillmigrate froma traditional roleofdemand management, where traffic is constrained against available capacity, to one of networkoptimisationandcapacityfacilitationitmustbecomeavaluepartnerfortheusercommunity.2.0.2 Ifdemandisthechallenge,thenitisimportanttounderstandhowandwherethatdemandwillpresent,andthelikelyeffectnotonlyatindividuallocations,butacrossthenetwork.

2.1 ForecastDemand2.1.1 Thenumberofaircraftoperating throughAustralianairspaceand intoAustralianairportshasbeen increasing consistently through the last 30 years. On average, according to BITRE3, passenger

movements have increased by 5% p.a.,whilstaircraftmovementshaveincreasedbyaround1.5%p.a., in thesameperiod.The disparity between passenger andaircraftgrowth rates is related toseveralfactors, including the pilots strike in1989/90,the9/11terroristattackandthecollapseofAnsett in2001,andthemovetolargeraircraftwithgreaterloadfactors.Without these factors, aircraftmovementsmayhave risenbyaround23%p.a.

2.1.2 Planning for future services requiresanunderstandingofhistorical trendsand currentactualmovementdataandaccurateforecasting.Therearecurrentlyseveralsourcesofactualandforecastdatahowever,nonearespecificallytailoredtotheneedsofnetworkmanagement.

Enroute2.1.3 For theenrouteenvironment, theonly readilyavailable trendand forecastdata comes fromBITRE. There is some corroborating information from ICAO and the International Air TransportAssociation(IATA)butnotataleveloffidelityforAustralianplanningpurposes.Actualmovementdata

3BureauofInfrastructure,TransportandRegionalEconomics

Fig1:HistoricalAirPassengerandAircraftMovements

throughallAustralianAirports(BITRE,2009ResearchReport117AircraftMovementsthroughCapitalCityAirportsto2029/30)


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wholeofsystemandsectorbysectorisavailablewithinAirservicesbutiscurrentlydifficulttoextractandutilise,anditsconsistencyisproblematic.2.1.4 ForecastdataavailablefromBITREindicatesanaverageyearonyeartrafficdemandgrowthof3%. In some areas (Western Australiaresource areas, Queensland oil and gasfields) thedemand growthwillbehigher.Intheabsenceofsoliddata,itisdifficulttopredictthegrowthfiguresbutitislikelytobe in the order of 5% p.a. in the shortterm. There is some evidence that thegrowth in Queensland regional serviceswill cascade through toBrisbane this isevidencedbyaforecastgrowthof4%p.a.at Brisbane Airport4 for the next 5 years(levellingat3%intheoutyears).2.1.5 Intheshortterm(+5years),thecurrentkeytrafficcorridoroftheJCurveisandwillcontinuetobethemostcriticalnetworkmanagementarea.Thisisborneoutbythediscussiononairportsbelow.TrafficflowmanagementintoandaroundPerthAirportisalsolikelytobecomeanincreasingfocusarea.2.1.6 In the medium and longer term, as eastcoast major airport capacity is absorbed, enrouteairspacefeeding intotheJcurvewill increasinglybesubjecttonetworkmanagementconstraints.Thiswillbeexacerbatedby increased focusonuser requirements for increased flightefficiency (e.g.,userpreferredroutes)andtheneedtomanageaircraftemissionsprofiles.

Airports

2.1.7 Airportforecastdataisavailablefromanumberofsources.First,themajorcapitalcityAirportMaster Plans provide an airports view oftraffic growth. From those plans, trafficgrowth is forecast atbetween 2% and 4%year on year with Brisbane forecast ataround 3.5% p.a., Melbourne at around2.2% p.a., and Sydney at around 2% p.a.BITREhasprovidedanumberofdatasetssomebasedonGDP growth,othersbasedon historical trend. Airservices airportmovementdataismoreaccurateandhelpsto establish historical trends but

4BrisbaneAirportMasterPlan2009

Figure2:ExpectedCapitalCityTrafficGrowth

Figure3:DetailedAverageHourlyMovementAnalysisML/SY/BN


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forecastingisproblematic.2.1.8 It is important to note that whilst a difference of 1% in notional growth rates will have amarginaleffectonshortterm(+5years)predictions(e.g.,17%vs.20%growth),thatsamediscrepancycanhaveasignificanteffectonlongterm(20years)predictions(e.g.,70%vs.100%growth)whichinturncanhaveasignificanteffectoninvestmentdecisions,capabilityoptions,andsoon.

2.2 NetworkEffect2.2.1 Networkeffect refers to thephenomenon thatdemandneedshourlyairportcapacityatboththedepartureandthedestinationairport,attheappropriatedepartureandarrivalhourofeachflight.Ifone of the airports on an airport pair is more congested than the other, the less congested (oruncongested) onewill suffer from unaccommodated demand, even though it has sufficient capacityitself.2.2.2 Whereonlyone citypair airport is critical (e.g., Sydney)andother airports (e.g.,BrisbaneorMelbourne) have capacity, the network effect is relatively benign. However, as traffic grows theinterdependencybetweencitypairairportsbecomescritical.By2020,forexample,bothMelbourneandBrisbanewillhavetrafficdemandatthesamelevelasSydneycurrentlyexperiencesandSydneyitselfwillhave30%moretraffic.2.2.3 Asshown inFigure3 thisdemandoverlaps for substantialperiodsof theday ifoneairportexperiences capacity shortfall, itwill cascade critically through thenetworkand throughothermajorairportsandoutintotheregionalfeederairports.Solutionscurrentlyavailablee.g.,airborneorgrounddelayprogramswilllosetheireffectiveness,complexityincreasesandparkingspaceisnotavailable.

2.3 OneaMinute2.3.1 Thehourbyhouranalysisand forecastsalsopresentanother challenge.Atpresent,with theexception of Sydney, airport peak and trough demand is such that disruptions caused by adverseweather, or other system disturbances can generally be absorbed across the day. As traffic grows,however,thescopeforabsorbingdisruptionswilldisappear,andtheflowoneffectsofadisruptionatanindividualairportwillbebecomesignificantevenwithoutthenetworkeffect(thisisalreadyevidentatSydneywhendelayedflightsconflictwithcurfewtimes).2.3.2 By2030,BrisbaneandMelbourneairportswillneedacapability to sustain60movementsanhour (onemovementaminute) forsignificantpartsof theday, inallweatherconditions.Sydneywillneed to be able to sustain demand of 80movements per hour (capped) for 15 hours a day, in allweatherconditionsandallrunwayconfigurations.


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3. OptimisingNetworkOperations3.1 Optimisation of network operations is essentially about the increasingly fine balancing ofvariablecapacityandvariabledemand toensurethateachavailablecapacityopportunity (airspaceorrunwayslot)inthesystemisconsistentlypresentedforuse,andthattheusersaregivenanopportunitytoconsistentlyaccess thatpresentedcapacitynot justatasinglenodeor location,butacross theirintegratedoperations.3.2 Incircumstanceswherecapacityconsistentlyexceedsdemand,there isgenerallynosignificantneedtointroducefloworcapacitymanagementinitiativesslotsarealwaysavailable,andareusedasrequired.Where there is competition for a particular slot, basicATC interventions (vectoring, speedcontrol,etc)managetheconflict.3.3 Inthepast,whereflowmanagementinitiativeswereintroduced,theirprimaryapplicationwaseither in the protection of the ATC system against overload, or tomanage environmental or otherexpectations at a particular node. Rarely were such initiatives implemented for the benefit of thebroader stakeholder community.Now,wheredemanddoes start to regularlyexceed capacity,whilstsome focus isplacedondevelopingnew capacity, given the long lead times formajor infrastructureimprovements (new runways, taxiway upgrades, new parking gates etc)most emphasis is onbetterutilisationofcurrentlyavailablecapacityorinmanycases,simplytransferringthecapacityshortfalltotheuserthroughgrounddelayprograms,demandlimiting,andsoon.3.4 This is exacerbatedby the traditionally tactical and reactivenatureof the system from anANSPperspectiveaircraftaremanagedastheypresentona firstcomefirstservedbasis,andfromauser perspective aircraft are presented to the systemwhen they are ready, generally regardless ofscheduled times. It is furtherexacerbatedby theopennatureof thesystem that is, the inability toconsistentlycontrolsignificantvariablessuchasweather,systemoutages,landsidedisruptions,etcandtherelativelackoffidelityinstrategicforecastingandtacticalinterpretationofavailablecapacity.Toalargeextent, given the relative situational awarenessmonopoly,networkmanagement is currently aunilateraldecisionmakingprocess,managedbytheANSP.3.5 Effectively managing the expected increase in traffic demand within a limited capacityenvironment,whilstpromotinganenvironmentwithinwhichairspaceuserscancontinuetogrowtheirbusinesses,requiresachange innetworkmanagementparadigmthatintegratesamuchlargervolumeofsituationalawarenessinformation,andestablishesanincreasinglyfinegranularityofdecisionmakingand business rules. This cannot be done unilaterally it requires distribution of responsibilities,flexibilityinsystemresponsiveness,andintegrationofmanagement.3.6 The key to further improving demand/capacity management is in utilising all availableinformationfromaffectedstakeholderstosupportacollaborativeenvironmentwhereallstakeholdersparticipate indetermining thebestactions tobalancedemandagainstavailablecapacity.This isbestachieved through the implementation and use of collaborative decision making capabilities.


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4. UserFocusedNetworkManagement4.1 Enhancementofnetworkmanagementisessentiallyauserdrivenperformanceexpectation.Indevelopingnetworkmanagementcollaborativedecisionmakingstrategiesitiscriticaltounderstandthecustomers operating model, and, working with the customer and other stakeholders, to sustaincustomervalue.Thisisnotsimplyaboutcollaborationinthedaysandhoursbeforeaflightitisaboutintegrating planning processes and cycles at all points in the customer planning cycle from VeryStrategicthroughStrategic,Pretactical,TacticalandimportantlyPostTacticalforperformanceanalysis.4.2 The airline elements in Figure 4 below (based on an IATA model) are typical of an airlineplanningcyclevariationscanbemadetorepresentmilitaryandbusinessaviationplanningcycles,butthegeneralflowremainsthesame.

Fig4:FutureANSP/AirlineNetworkManagementInteraction

4.3 At present, the collaborative interaction betweenANSPs and the user tends to occur in theTactical and PreTactical timeframe. In the evolution of network management, the collaborativeprocesseswillextendthroughallphasesofthecustomerplanningcycle.4.4 Itsalsoimportanttounderstandthekeyperformancecontexti.e.,whyairlines(andusersingeneral)wantorexpectimprovementsinnetworkoperation.Mostcurrentperformancegoalsaroundflow and network management centre on delay reduction and ontime performance. These areimportantfactorsforairlines,astheyrelatedirectlytoschedulemaintenance,whichinturnrespondstotwodriverspassengerexpectations,andcriticallyforanairline,aircraftutilisation.4.5 Anairlines investment inaircraft issubstantial,and it iscriticalthattheairlinecanoperate itsscheduleaspredictablyandreliablyaspossible,withasfewaircraftaspossible.


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4.6 Therealityofthelast3040yearsisthatairlineshaveadjustedtheirschedulestocaterfortheunpredictabilityandunreliabilityofATMnetworkoperationasawhole.Often,thescheduledtimeforaflightof,say,onehour(e.g.,MelbourneSydney)willbeshownasalmost2hours.Withanaddedturnaroundofonehour, theentire cycle foranotionalonehour flightbecomes3hours.Thisnominallylimitsthecyclicaircraftutilisationto8flightsaday.Animprovementinpredictabilityofjust30minutesperflight(i.e.,2hourspercycle)canincreasedailyaircraftutilisationbyalmost2flightsaround20%.

Fig5:AircraftUtilisationCycleATMandNetworkManagementEnhancementOpportunities

4.7 ANSPscontributetothisimprovementincycletimeinthreeways.ThefirstisbyimprovementstooperationaltrajectoriesmovingtowardsUserPreferredTrajectoriesthroughanATMImprovementprogram.4.8 The second and more significant contribution will come from improvements to networkmanagement, improvingpredictabilityandconsistency,sothatairlineswillhaveconfidencetoreducescheduledoffblocktoonblocktimes. Inaddition,byreducingtheneedforgroundholding,therewillbeasmallcontributiontothereductioninonblocktooffblocktime.4.9 The third contributionwillbe in theprovisionof collaborativedecisionmaking capabilities tofacilitateimprovementstoairportmanagementmostsignificantlyoptimisationofairportturnaround.4.10 Theairlineexpectation is thatacumulative improvement in the threeareasATM,NetworkandAirportperformancewillallowanincreaseinaircraftutilisationorsignificantlyareductioninthenumberofaircraftrequiredtooperateaschedule.


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5. AirportsTheCriticalNode5.1 Airportsarecriticalnetworknodes.Foranydiscussionofenhancingnetworkmanagementit isimportant to understand some of the key factors affecting airport performance.Airports facemanychallenges economic, commercial, political, operational, environmental and/or regulatory. Coupledwithphysicalairport landandairspaceconstraints,these influencethe longertermstrategiesandtheability of airports to proactively develop new capacity or to provide infrastructure to mitigatecongestion.5.2 CongestionisalreadyalimitingfactoratanumberofAustraliasairportsforatleastsomepartofthedayastrafficdemandincreasesthroughthenext20yearsitwillbecomethemajorconstraintonnetworkperformance.Furthermore,futuretrafficgrowthislikelytogeneratecongestionatairportsthatarenotyetexperiencingcapacityproblems.5.3 Thereareseveralairportrelatedfactorsaffectingnetworkperformancebuttwoarecritical.Thefirst is taxiway availability and management i.e., the ability to get aircraft to runways in anappropriatelysequencedandtimeorderedmanner,andtheabilitytogetaircraftfromrunwaystogateswithout causing congestion. The second is consistent and predictable apronmanagement i.e., theabilitytoreliablyturnaircraftaroundatparkinggatestomeetnetworkordeparturetimerequirements.5.4 Establishingnewinfrastructuretoachievethesegoalsfromparkinggatesandapronsthroughtotaxiwaysandrunwaysrequireslongleadtimesandsignificantcapitalexpenditure.Requirementsforaerodrome facilitiesaredevelopedasacomponentofanairportmasterplanwitha20yearhorizon.Theyaregenerallydeterminedonthebasisofforecastingandmodelling inconsultationwiththeusercommunity and to a lesser extentwith theANSP. Clearly in the short tomedium term themostrealisticoptionistoutiliseexistinginfrastructuremoreeffectively.

Fig6:Airport/AirlineNetworkManagementInteraction


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Taxiways5.5 Taxiways are the airport arteries, connecting runways to parking areas. Given the longdevelopmental lead times, landandother infrastructureconstraints (e.g., roadunderpasses,electricalducts,etc)andcost,taxiwaysarestrategicallydesignedtobestfacilitatethemostcommonlyoperatedaircraft or runway operating modes and available real estate. Consequently, taxiways and runwayentry/exitscannotbeoptimalforallaircrafttypesoroperatingmodes.Lackofphysicalspaceandthefact that taxiways generallyonly allow aircraft tooperate single file inonedirection precludes theprovisionofcapabilitytoadjustaircraftsequencesatoronthewaytoholdingpoints.5.6 Whereslottimecompliancerequirementsarerelativelycoarse(e.g.,15minutes),thisdoesnothaveasignificanteffectonthenetworkbutascompliancerequirementsbecomefiner(e.g.,takeoffslottime1minute)taxiwaymanagementwillbecomecriticaltonetworkperformance.Fromanetworkmanagement perspective, therefore, it will become increasingly essential that the use of existingtaxiways, runways and runway exits is planned and coordinated to a high level of fidelity across allaffectedstakeholders.

ApronManagement5.7 Apron turnaroundperformance (i.e., themanagement of an aircraft from onblocks to offblocks) is affected by a number of factors. These include operations related to determination andallocation of arrival gates or parking positions, deconfliction of traffic on aprons,management andmanipulation of aircraft onto and off gates or parking locations, and allocation of groundhandlingequipmentandloading/unloadingresourcetoanaircraft.Italsoincludesalloftheelementsrelatingtopassengermovementinaterminal,luggageandcargomanagement,aircraftmaintenanceandgatereallocation, dispatch activities, contingency gatemanagement and a range of other activities. Theseoperationsareoftenmanagedbydifferentstakeholders.Itisthesumoftheseelementsthatcontributetotheturnaroundtimeofanaircraft.5.8 Anyoneoftheseelementscan leadtoadelayagainstATMagreeddepartureorarrivaltimes,negotiated in some casesmanymonths in advance. TheATM system is not currently configured tocoordinate these activities however, airlines deal with them on a daily basis, and have clearlyestablishedproceduresformanagingthevariouscomponents.Extendingthisdailycollaborationacrossall stakeholders including the ANSP will ensure that a greater focus is placed on networkmanagement. This is best achieved through the implementation and use of collaborative decisionmakingcapabilities.5.9 Managing turnaround time isobviously important fornetworkmanagementbut forairportoperatorsthereisanotherkeybenefit.Currentlyschedulingunreliabilityforcesairportoperatorstoupto10%ofgates to facilitate offscheduleoperations. In thecaseofa terminalwith30gates3gateswouldbesetaside. Ifoneof thesegatescanbemadeavailable forplanning rather thancontingencypurposes,notionalgatecapacityandthereforesystemcapacity couldbe increasedbyuptosevenaircraftoperationspergateperday.


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6. CollaborativeDecisionMakinganOperationalConcept

6.1 Overview6.1.1 The benefits of using Collaborative Decision Making (CDM) for enhancement of networkmanagementareverywideandvaried innature.Evenatthemostbasic levelofpurely improvingthedistribution of existing information amongst users and stakeholders, thereby creating commonsituationalawareness,significantbenefitscanbeachievedwithrelativelylowinvestment.6.1.2 Common situational awareness requires anew approach to information sharing;however itsinitial implementationdoesnotrequiremajor investment in informationnetworks. Itcanbeachievedinitially by simply interfacing existing systems to provide better quality data based on commoninformationelements and interactions.This interfacing can starton an adhocbasis initially,butwillrequiretheprogressivedevelopmentandintroductionofcommonlyagreedstandardsandproceduresultimately leading to the development of an integrated systemwide informationmanagement (anddistribution)capability,supportedwithenhanced(aeronautical)informationmanagement.6.1.3 To realiseall thepotentialbenefitsofCDM through thenext20yearsallof the componentsdescribed in this operational conceptwill need to be implemented and a networkwide approach isnecessary. In practice, a phased, bottomup approach will have to be followed, with eachimplementationstepdeliveringanincrementalbenefit,whichwillbecomeevenmoresignificantastheCDMconceptcomponentsmatureandareimplementedmorebroadly.6.1.4 Some of the components particularly those related to airport optimisation cannot beimplemented in isolation to work effectively they require the implementation of supportingcomponents.As indicatedpreviously, thisdoesnot imply theneed to implement technologybut itdoes require the establishment of procedures and practices that provide the base capability of theunderpinning component. The operational concept therefore assumes that some components areimplementedbeforetheothersareconsideredorareimplementedinparallel.6.1.5 Theoperationalconceptalsoassumesthattheexistingdata(situationalawarenessanddecisionmaking)and informationmanagement infrastructurewillremain,withchangestoexistingsystems(ordeployment of new systems) kept to the minimum required to support the implementation of thecomponents.Inallcases,costeffectivenessmustbeaprimaryconsideration.6.1.6 Providing information and better quality network management induces costs for allstakeholdersthatshouldbebalancedbyhigherbenefits.Arguably,theprovisionofinformationbyoneparty that improves network overall management has a value, and that value should be reflectedthroughquantifiableandmeasurablebenefitboth to theprovider (returnon investment),and to theothernetworkstakeholders(crossindustrybusinesscase).


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6.1.7 Accordingly, inorder toquantify thebenefits it is important toobtain an agreementonKeyPerformanceIndicatorsandtheuseofrecordeddataforevaluationpurposes.Posttacticaldataanalysisisanimportant,requiredactivitywithaviewtomonitoringandimprovingallCDMrelatedactivities.6.1.8 Inaddition,forallcomponents,appropriateproceduresareneededtoenableCDMstakeholderstodiscussissuesandimprovementsandtoagreeonactionifapartnerdoesfulfillitscommitment.

6.2 ALayeredApproach6.2.1 CDM comprises a number of components and is applied at several layers, each one actingsequentially with an increasingly fine level of network performance granularity but with anincreasinglyhigherlevelofperformanceresponsibilityon,andcollaborativeengagementbetweeneachinvolvedstakeholder.6.2.2 ThefirstlayerfocusesonwholeofsystemDemandandCapacityBalancingandisestablishedonanAustraliawidebasis though applicationmay initiallybe restricted to certain timeperiods,or tocertain specified areas/traffic flows. The second and third layers respectively focus on CapacityOptimisationandNetwork(orSchedule)Optimisation,andareappliedonalocationspecificbasisi.e.,foraparticularmeteringpoint,foranairspacevolume,ormorepredominantlyforaparticularairportorsetofairports.

Figure7:CollaborativeDecisionMakingforEnhancedNetworkManagementComponents


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6.2.3 Layer onehas two components GatetoGate FlowManagement, andArrivalOptimisation.Layer two has four components Arrival Optimisation, Apron TurnAround Optimisation, DepartureOptimisationandIntegratedRunwayManagementi.e.,theintegrationandoptimisationofarrivalsanddeparturesstreamsataparticularairport.ArrivalOptimisationisanextensionofthesamecomponentatLayer1,butfocusednowoncapacityoptimisation.6.2.4 The third layer has four components Airport Turnaround Optimisation, DepartureOptimisation,integratedArrivalandDepartureOptimisationandNextAirportIntegration(integrationofdeparturesatoneairporttonextairportarrivals).Thefirstthreeofthesecomponentsareextensionsofthesamecomponent inLayer2,butwithhigherfidelityrequirementsandaspecificfocusonnetworkoptimisation(i.e.,fortheATMnetworkasawhole)andforairlines,scheduleoptimisation.6.2.5 Thecomponentsinlayers1and2focusonprocessesthatneedtobeestablishedtoachieveanoutcomethisneednotnecessarilyinvolvedeploymentoftechnicalortechnologicalsolutions(atleastnotinthefirstinstance),butmaysimplyinvolvethedevelopmentandpromulgationproceduresbasedbusiness rules e.g., traffic management procedures, prioritisation instructions, standard taxiwayroutes,etc.InLayer3,moresophisticatedcapabilitiesandhigherfidelitycollaborativedecisionmakingprocessesaredeployed.

Figure8:CollaborativeDecisionMakingLayeredApplication5

6.2.6 Each component is supported at increasing levels of granularity by Local and System WideInformationManagementcapabilities,collaborativedecisionmakingprocessesandprotocols(businessrules),andenhancedsituationalawarenesscapabilitiessuchasASMCGS.6.2.7 EachlayerofCDManditsassociatedcomponentsalsoinvolvestemporaldecisionmakingthatis, the decisionmaking processes are not simply conducted on the day of flight but involvemultistakeholderinteractionsintheStrategic,Pretactical,TacticalandDynamictimeframestoestablishthebusiness rules foroptimumnetworkperformance.Necessarily the levelof fidelityofdecisionsmade

5Thediagramisillustrativeonly.Therepresentationofgatetogateflow,forexample,ismeanttoindicateapplicationacrossthenetworkbutnotwiththelevelofgranularityofarrivalanddepartureoptimisation.Itisalsomeanttoindicatethatgatetogateflowdoesnot(significantly)encompassairportoperations.


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furtheraway from theactual timeof flightwillbe influencedby theavailabilityandqualityofsystemdataandinformationandtheabilitytopredict,forecastandmanagesystemdisturbancessuchasweather,airspacerestrictions,etc.6.2.8 Each layerofCDMalsochanges the levelsof responsibilityofstakeholders.Forexample,theeffectiveoperationofgatetogateflowis primarily the responsibility of the ANSP however, the effectiveoperation of turnaround optimisation at an airport is primarily theresponsibilityofairlinesinconcertwithairports.

CDMComponent

PrimaryOutcomes

StakeholderCompliance

AvailableSituationalAwareness

SharedSituationalAwareness

StakeholderInformationSharing

Layer1:DemandandCapacityBalancingGatetoGateFlow PreventionofATCoverload

Reductioninairbornedelay

FlowUnit:HighATC:MediumUser:Low

High Low Low

ArrivalOptimisation

Betterflowtospecificairports Slot/regulatorycompliance

FlowUnit:HighATC:HighUser:Medium

High Low Medium

Layer2:CapacityOptimisationArrivalOptimisation Arrivalintegrationforcapacity

Collaborativeprioritisation Increasedpredictability

FlowUnit:HighATC:HighUser:Low

High Medium Medium

ApronTurnAroundOptimisation

Betterpredictabilityfordepartureplanning

PrecursortohigherfidelityAirportCDM

FlowUnit:HighATC:HighUser:MediumAirport:Medium

High Medium Medium

DepartureOptimisation

Structureddepartureslotallocation

Collaborativeprioritisation

FlowUnit:HighATC:MediumUser:Medium

High High Medium

IntegratedRunwayManagement

Runwaycapacityoptimisation Increasedairportefficiency

FlowUnit:HighATC:HighUser:Medium

High High Medium

Layer3:NetworkandScheduleOptimisationAirportTurnaroundOptimisation

Collaborativedecisionmaking Distributedresponsibilities Enhancedapronmanagement Focusonnetworkperformance

FlowUnit:HighATC:HighUser:HighAirport:High

High High High

DepartureOptimisation

Precisetakeofftimeallocation Collaborativeprioritisationandslotreallocation

Betterapronmanagement


High High High

ArrivalDepartureOptimisation

Runwaycapacitymaximisation Increasedairportefficiency


High High High

NextAirportIntegration

Collaborativedecisionmaking Distributedresponsibilities Focusonnetworkperformance


High High High

Table1:CDMComponentOverview

Fig9:TemporalApplication


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6.2.9 Asalreadyindicated,CDMacrossthenetworkisoperatedwitharangeoflayeroptionssomeairportsornodesapplyingmore layers thanothers,withminimaloverallnetworkeffect.However,astraffic demand increases, and the network effect becomesmore dominant, itmay be necessary forstakeholderstoanticipateandacceleratethedeploymentofadditional layers.Onthisbasis,the initialdesign of the situational awareness (surveillance, communications, etc) and information sharingcapabilities (SWIM,AIS/AIM/IM, etc)must anticipate theneed for extended applicationwellbeyondinitialsystemdesignrequirements.6.2.10 Aseachlayerisimplemented,theemphasismovesfromthemanagementofindividualaircrafttoa specific slot, through to themanagementofslotsasawhole,where thecritical consideration iswhatneedstobedonetoensureanavailableorreleasedslot isutilisedbyanyavailableaircraft. It isalsoaboutslotusageratherthanslotcompliance.Thisistheultimategoalofnetworkoptimisationbutitrequiresahighlevelofengagementandcommitmentacrossallstakeholders.

6.3 Layer1:DemandandCapacityBalancing

GatetoGateFlowManagement6.3.1 Gatetogate flow management is responsible for (relatively) coarse optimisation of overalltraffic flow through the network, and intervention to prevent overload at specific locations whendemandexceedscapacity. Ingeneral terms itconcentrateson setsof individual flightsegments fromtakeofftolandingthoughtheregulatingoftrafficflowmay(andgenerallywill)requiregrounddelaywhichmayhavedisruptivedownstreamflowthrougheffectsonuserschedules.

Figure10:GatetoGateFlow

6.3.2 Despite the relative coarseness or granularity of individual slotmanagement, air traffic flowmanagement is actually supported by highfidelity situational awareness capabilities for monitoring


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systemcapacityandsystemdemand(partlybecauseitalreadyexists,butmostlytofacilitateintegrationwiththenextlayerswhen/whereapplied).Italsoprovidesamechanismformanagingtrafficflowswhenimbalancesoccur.6.3.3 Theairtrafficflowmanagementsystemmonitorflightsarrivingatanddepartingfromairportsingeneral,andcriticalairportsinparticular,whiletrackingdemandandcapacity.Thesystemalsomonitorsairspacevolumes,andcriticalnodes(entry/exitpoints,holdingpoints,etc).Whenan imbalanceexists,usersareabletoanalysedataandmodeldemandmanagementandoptionstodeterminetheoptimalsolutionformanagingtheimbalance.Onceasolutionhasbeenidentified,thesystempermitstheotheruserstoviewandparticipateinrefiningthesolutiontoreachamutuallyagreedposition.6.3.4 Air traffic flow management system tools allow modelling to take place in the strategictimeframei.e.,inthe612monthpreflighthorizontoenablegeneralrefinementofschedules,anddevelopment of initial network operations plans. Themain limiting factor at the strategic horizon isfidelity of capacity information at best historical averages can be applied but known capacityshortfalls(scheduledworks,knowndeficiencies)canbefactoredatthisstage.6.3.5 Airtrafficflowmanagementismosteffectiveinthepretacticaltimeframetypicallyinthe448hours preflight horizon where potential tactical constraints (works, staffing, rosters, equipmentavailability,etc)canbemitigated,andonlydynamicvariables(weather,systemfailure,etc)remain.6.3.6 Thereareanumberof limitingfactorstothenetworkwideeffectivenessoftheairtrafficflowmanagement layer though for some stakeholders these are in fact system positives. In general,allocatedslotstendtohavewidecompliancemargins(e.g.,15mins,or5mins/+10mins,etc)whichprovidearelativelysubstantialbufferforairlinesaboveandbeyondbuilt inschedulebuffers.Thiscanresultinaperceptionthatdemandandcapacityisbalanced,butarealitythataircraftarestillsubjecttodeparturedelays,orenroute/terminalareatrajectoryadjustment.6.3.7 Themoresubstantialshortfallisthedownstreameffectofimposinggrounddelayonindividualflightsthatcascadesthroughthenetworkparticularlywhenanindividualaircraftisoperatingmultiplelegsinahighdensitycorridor(e.g.,MelbourneSydneyBrisbane).6.3.8 In the current demand environment this can generally be managed by tactical or dynamicinterventiontoprioritisecertainindividualflightsbutasdemandincreases,andcapacityisreachedorexceededmoreregularly,implementationofhigherfidelitymanagementwillberequired.

ArrivalOptimisationFlowFocus6.3.9 Thegatetogateflowfunctionisrelativelycoursewithwidecompliancemargins.Wheretrafficflowsareconcentrated(e.g.,eastcoastofAustralia)itisbeneficialtoimplementcapabilitiesforbetteroptimisationofflowsintoparticularairports(e.g.,Sydney,Melbourne,Brisbaneetc).


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6.3.10 Arrival optimisation begins the process of introducing targetwindows ofmetering times foraircraft. Italso introducesthe integrationof tacticalandpretactical flightstreams i.e., itallowstheintegrationofaircraftwaiting todepart foraparticulardestinationwithaircraftalreadyairborneenroutetothatsamedestination.6.3.11 SuchcapabilitieswilleventuallyevolvefromaLayer1DemandandCapacityBalancingroletoaLayer2CapacityOptimisationroleandshouldbedevelopedtosupportsuchanevolution.6.4 Layer2:CapacityOptimisation

ArrivalOptimisationCapacityFocus6.4.1 Withinthenetwork,asdemandincreases,theflowoftrafficthroughcertainkeynodesbecomesincreasingly critical to capacity and specific focused management processes need to be applied. InAustralia thosenodesarekeyairportson theeastcoast (Sydney,Melbourne,Brisbane) togetherwithPerthintheshortterm,withthesetlikelytoexpandthroughthenext20years.6.4.2 Itwillbecomeincreasinglyimportanttomorepreciselyregulate/metertheflowoftrafficattherunways associated with these airports, and at particular airspace nodes around these airports, toensureboththatallavailablecapacityisutilised,andincreasinglythattrafficispresentedtorunwaysinarrivalsequencesthatbestmaximisecapacity(taking intoaccountweather,waketurbulenceetc),andcompanypreferencesforarrivalpriority.6.4.3 Arrival sequence optimisation aims to enhance runway capacity through sequencing andmetering the flow of aircraft entering a particular airspace volume(s) such as a TMA, to providepredictabilityandatthesametimeminimisethe impactontheenvironment,byreducedholdingandlowlevelvectoring.

Fig11:ArrivalOptimisation


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6.4.4 Tomeettheseobjectives,arrivalsequenceoptimisationprovidesasequenceattherunway,andanexpectedtimeattherunwayorthetimeat/overdifferentfixes(togetherwithapplicabletolerances).Itgivespriority to lineardelayabsorptions (i.e.,grounddelay, speed control,path stretch) insteadofholding patterns. Planning functions also help to reduce controllerworkload, particularly in case ofsystemdisturbance(suchasrunwayclosure).6.4.5 Whilst the development of business rules for arrival sequence management occurs in thestrategictimeframe,itsapplicationismostdominantinthepretacticalphase(forshorterhaulflights),orinthetacticaland/ordynamicphaseofnetworkmanagementforlongerhaulaircraft.6.4.6 Arrivalsequenceoptimisationrequiresahigher levelofcompliance(withfixtimes,sequencinginstructions etc) butwhilst it provides a higher level of predictability (about specific aircraft) andresponsiveness (at specific airports), it is not necessarily designed to enhance overall networkeffectiveness.6.4.7 Thekeybenefitisflexibleandadaptiveresponsivenesstoachangingoperationalsituation,suchascontrolleractions,revisedoperationalcapacity,reprioritizationandweatherimpacts.

ApronTurnAroundOptimisation6.4.8 Optimisationofarrivalstreams isonlyonepartoftheairportcapacityenhancementequation.To fullyoptimise capacity it isnecessary tomanage thedeparture streams,and topretactically andtacticallyintegratearrivalanddeparturestreams.Thisisnotsimplyacaseofallocatingacertainblockofarrivalsand/ordeparturesperhourthisisaboutincreasingthepredictabilityofdeparturessothattheycanbeallocatedspecificdeparturetimesorslots.6.4.9 Todothiseffectively,itisnecessarytohaveadegreeofcontrolorpredictabilityaboutaircraftturnaroundontheaproni.e.,tohavesomecommunicatedcertaintyaboutwhenaircraftwillbereadytopresentintothedeparturestream.6.4.10 In Layer 2, theATC/airline levelof fidelity is relatively fine but the airline/airportbuffer isrelativelylargethatis,thescheduledpushbacktimesforairlinestakesintoaccountthepotentialturnarounddisturbances.Theairportandgroundhandling componentsarenotpartof theATMdecisionmakingprocessatthislayerthisoccursformallyintheairportturnaroundoptimisationinLayer3.6.4.11 ApronTurnAroundOptimisation isanecessaryprecursor toLayer2 (andLayer3)DepartureOptimisation.

DepartureOptimisationCapacityFocus6.4.12 Departure optimisation at Layer 2 is primarily focused on increasing capacity at particularairports. The aim is to better predict specific departure stream demand, and to be able to flow


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departurestreamtraffictorunwayholdingordeparturepointsinsequencesthatnotonlyoptimisetheterminalareamanagement,but alsopresentaircraft to theenroute flow inaway that reduces theneedfortacticalintervention(e.g.,ensuresspacingbetweentwoaircraftboundforthesamedestinationissufficienttoavoiddownstreamholdingorpathstretching,etc).6.4.13 The fidelity of departure optimisation is critically related to the predictability of apron turnaround better apron predictability allows better departuremanagement and better integration ofdepartureswitharrivalstreams.Becauseoftheuncertaintiesassociatedwithapronmanagement,Layer2departureoptimisation is apretactical and tactical function,with strategic actionbeing limited tobroadscheduleplanning,andairportinfrastructureoptimisation.6.4.14Departuresequenceoptimisationasasecond layerCDMapplication ismorecriticalatairportsthat alreadyhave,or anticipatehavingdeparture capacity constraints. Those airports thathavehighlevelsof taxiwayor runway flexibilitywillnotnecessarilyneed to apply it,but it is anecessaryprerequisitefor implementationofthird layerCDM6andforeffective integrationofarrivalanddeparturestreams.

IntegratedRunwayManagement6.4.15 Havingestablished separateprocesses foroptimisationofarrivalanddeparture streams,anddeveloped processes for increased apron turn around predictability, the next natural component ofcapacityoptimisationistheintegrationofarrivalanddeparturestreamstomaximiserunwayutilisation.6.4.16 The aim of integrated runway management is to manipulate aircraft in both arrival anddeparture streams to provide deconflicted arrival and departure slot opportunities. This can beachievedtacticallythroughtimebasedtargetwindowallocation(e.g.,3minutespacingatarrivalfixes,2minutespacingbetweenlandings,etc)ordynamically(e.g.,ATCpathstretchingtoachievea6or7milespacingbetweenarrivalstoallowadeparture).6.4.17 Giventheleveloffidelityofthevariousstreams,itislikelythatatlayertwo,integratedrunwaymanagement will be a tactical/dynamic function, with pretactical actions limited to broaddeterminationofperhourarrival/departuremix,andrunwayconfigurationacceptancerates.6.5 Layer3:Network(Schedule)Optimisation6.5.1 In layersoneandtwo, thepredominant focushasbeenonthe interactionbetweentheANSP(ATC and Flow Management) and theUsers to determine optimal flow and sequencing. To a largeextent,theoperationofthevariouscapabilitiesintheselevelsisbasedonarelativelylargeembeddedturnaroundperformancecomponent inuser schedules,updatedona reactivepretacticalor tacticalbasiswhenflightsareinapositiontobeginthenextflightsegment.6Theprerequisiteistheprocessitmaybeasetofproceduresorprioritisationrulesnotnecessarilyatechnologyortechnicalcapability.


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6.5.2 Inaddition,theflowandsequencingcapabilitiesforarrivingstreamsisineffectterminatedonceanaircraftissufficientlyfarfromarunwaythatitspositionwillnotinterferewithfollowingoperations.Levelsoneandtwoaregatetogatefocusedormorepreciselygatetoapronorgatetoarrivaltaxiwayandmanageseriesorblocksof individual flightswithoutconsiderationof the next flight segment.Effectivelythemanagementclockresetsforeachflight.Levelthreeisaboutintegratingthoseindividualflightsandeffectivelymanagingairlineschedulesandwholeofnetwork.6.5.3 Whole of network efficiency is highly dependent on traffic predictability which is in turndependentoncommonandsharedsituationalawarenessacrossamuchbroaderrangeofstakeholdersthan involved in layer one and two most critically airports. It also requires a broadening of theresponsibilityenvelopwithmorepartnersinvolvedandmoredecisionmakingpoints.

AirportTurnaroundOptimisation6.5.4 Currently,where there isno effective linkagebetween airborne and ground flight segments,deviationsfromtheplannedtrafficsituationwillnotbetransmittedtothenetwork.TheknockoneffectthatdeviationsfromtheplanproduceonthenetworkarenotanticipateddownstreambyairlinesortheANSP. This will result in a large number ofmissed slots or noncompliancewith the slot allocationrequirementsandassuchininefficientuseoftheavailableenrouteandairportnetworkcapacity.6.5.5 Unlike apron turn around optimisation, which is focused on increased predictability forindividualflights,airportturnaroundoptimisationisaimedatenhancingpredictabilityandreliabilityonthe ground for all ground flight components (taxiin, parking, ground handling, push back etc), andlinkingthecompletionofoneflighttothestartofthenextbythesameaircraft(tailtracking).Itisaboutwholeofairporteffectivenessandefficiency.6.5.6 Itisprimarilyanairportgroundoperations/airlinecoordinationfunction;however,itscriticalitytowhole of network operations, and the fact that airports generally operate as independent nodeswithin theoverallsystem (i.e.,arenotdirectly interconnected) requires thedirectengagementof theANSP(Airservices)asacollaborativepartner,andasthe localandsystemwide informationmanager(andmajor situationalawareness informationholder).Airservices alsohas a significant role as a keydecisionmakerinthe(necessarily)integralarrivalanddepartureoptimisationcomponents7.6.5.7 To be effective, airport partners must work together and share data and informationmoreefficiently and transparently. The establishment of a common operational picture, with the samemeaning to all stakeholders, will allow improved decisions based on more accurate and timelyinformation. Thiswill allow each stakeholder to optimise their decisions in collaborationwith otherstakeholders,integratingtheirpreferencesandconstraintswiththeactualandpredictedsituation.7As indicatedpreviously thisdoesnot infer theneed (in the first instance) forarrivaland/ordepartureoptimisation technologyonly theprocesses/proceduresneedtobeinplace.


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Fig13: AirportTurnAroundOptimisation

6.5.8 Whilstan informationrichenvironment isessentialtoairportturnaroundoptimisation, italsohasasignificantpotentialto impedeperformance. Inthestrategictimeframe, intheestablishmentofthe business rules for airport turnaround optimisation, the most critical consideration is theestablishmentofhierarchicaldecisionmakingprocessesthatareaimedatensuringthatresponsibilityforcomplianceisdelegatedeffectivelysothatoverlapisavoided.Itisalsocriticaltoestablishlinkagestoarrivaloptimisationanddepartureoptimisationprocessessimplygettingaircraftinandoutofgatesorapronsontimedoesnotguaranteethataircraftcanactuallyreachadeparturepointatatargettime.6.5.9 Inthepretacticaltimeframe,thekeyfocusisonthepredeparturesequencingprocess.Oneofthemainoutputsoftheairportturnaroundoptimisationprocesswillbeaveryaccuratetargettakeofftime (e.g., 1minute)whichwillnotonlyenhancegroundplanningbut canbeused to improveenrouteplanningaswellastomoreaccuratelyplanthemanagementofthewholeofAustralianairspacei.e.,toenhancetheeffectivenessofthelevel1and2components.6.5.10 In the tacticalanddynamic timeframe, the focus isonensuring thataircraftaremanipulatedontoandoffgatestoensure thateitherapredeterminedtakeoffslot isachievedormorecriticallythatifitcannotbeused,itisimmediatelyavailableforusebyanotheraircraft.Thisrequiresimmediateornear immediateaccess todecisionmakingprocessesat theaircraft (eitherby thepilot,orgroundhandling staff)whenslotcompliance is indoubt, so that the slotcanbe reallocated,andanewslotdetermined.6.5.11 In order towork effectively, turnaround optimisation needs to be supported by arrival anddepartureoptimisation.There isnopointachievingahigh levelof fidelity ingettinganaircraftoffanapronifitisnotpossibletogettheaircrafttothedeparturepointorairborneontime,orfromanarrivalrunwaytotheapronsothatitsturnaroundclockcanbestarted.Asindicatedpreviously,thisdoesnotrequiretheimplementationoftechnologyitcanbeachievedprocedurally.


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DepartureOptimisationNetworkFocus6.5.12 DeparturesequenceoptimisationinLayer3aimstopresentaircraftfordepartureattherunwayholdingpointinasequencethatintegratestheusersdeparturetimeexpectation(schedule),anticipatespotential downstream arrival sequence or air traffic flow management requirements, andfactors/mitigatesthedeparturecapacityconstraints(network).Therearefourmajorconstraintsonthedeparturecapacityofanairport:

AircraftMixatRunway differentaircraftwakevortexstandards, runwayentryand rolltimerestrictions,etc

Terminal Area Departure Paths limitations of standard departure procedures,segregationofmultirunwaydeparturepaths,arrival/departurecrossovers,etc

Manoeuvring Options at Runway Holds availability of holding/runup bays, multiplerunwayentrypoints,etc

TaxiwayManoeuvringOptionsavailabilityofapronexitoptions,taxiwayoptions,etc6.5.13 Aswith Layer 2, departure sequence optimisation as a third layer CDM application ismorecriticalatairportsthatalreadyhave,oranticipatehavingdeparturecapacityconstraints.Itwillbecriticalfor those airports that have limited taxiway or runway flexibility. Departure sequence optimisationcomplementsandenhancesairportturnaroundoptimisationitisessentialtobeabletomoveaircraftfrom aprons to departure points optimally delays or congestion on taxiways degrades apronperformance.

Fig12:DepartureOptimisation

6.5.14 Business rules are developed in the strategic time frame, andwill factor average taxi times,typical terminal area airspace management practices, potential airline preferences, typical apronmanagement constraints, and so on. Pretactically, airline departure sequence preferences areestablished,andknownoranticipatedparkingpositions,taxiwayanddeparturerunwayconfigurationsetc are factored. Tactical application of departure sequence optimisation is focused not only on


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presenting aircraft in a particular order at the runway, but also on minimising dynamic delay andreducingqueuingi.e.,leavingstartupandpushbackaslateaspracticable.6.5.15 Departure sequence optimisation enables improved response and reaction to unforeseenevents and can therefore reduce the negative impact of such an event (e.g., instantaneous runwayclosuredue toaccident,weather changesetc).By constantlymonitoringanddistributing informationdeparture sequence optimisation enables dynamic plan updates based on the current situation andtimelydistributionoftheinformationtothedifferentoperatorsandstakeholdersattheairport.

Arrival/DepartureOptimisation6.5.16 As runwaycapacity is reachedmoreconsistently, it is important toensure thatan integratedapproach is taken to managing arrival and departure streams both to ensure that airport/gatethroughput is maintained, but more critically to leverage the constraints in each stream to createcapacityopportunities.6.5.17 This is particularly important when there are varying wake turbulence categories in arrivaland/ordeparturestreams(necessitatingalargerarrivalordepartureslot,withinwhichanotheraircraftmaybelandedordeparted),orwhenthereisanemphasisonarrivalsoverdepartures(orviceversa).Itis also importantwhenmultiple runways are being used for unifunctional streams (one runway forarrivals,onerunwayfordepartures)andtherearegapsthatmaybeutilisedfortheoppositefunction.6.5.18 In Layer 3, arrival/departure optimisation for the concept of high and consistent runwaythroughput requiresboth integrationof the arrivals sequenceoptimisation anddepartures sequenceoptimisation functionalityandahigh levelof informationsharingandsituationalawareness fidelity,and targetwindow compliance (from both users andATC), as the critical dependency is the preciseinterspersingoflandinganddepartingaircraftinahighworkloadenvironment.6.5.19 OfparticularimportancefromadynamicperspectiveistheinteractionbetweentheATCTowerfunction and the ATC Arrival/Approach function. Precise taxiway management is also essential toensure that the runway is vacatedwhen requiredby landing aircraft, and thatdeparting aircraft aredelivered to the runway threshold in the correct sequenceandat the time required inallweatherconditions. Airportroutingandguidanceaidsdeveloped inmoreadvancedfunctionsofASMGCS(forexample)areexpectedtocontributetoevenmoreprecisetaxiwaymanagement.

IntegrationofDeparturestoNextAirportArrivals6.5.20 Most airports operate as independent nodes within the ATM system and their individualoperationcanhavesignificantimpactoneitherupstreamordownstreamoperations.Thisisparticularlyimportant when those upstream or downstream airports are critical nodes, with high demand orcapacity constraints. The last component of the collaborative decision making framework is the


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integration of sequencing operations at one airport in particular departures with the arrivalcomponentofoperationsatthenextairportforanyparticularaircraft.6.5.21 This integration of planning across the network is essential from a user perspective for themaintenance of predictable schedules with schedule maintenance issues being amortised andmanaged across a series of flights (by the same aircraft). The aim is not, for example, to eliminatedelays,buttousetheintegratedsystemtoprioritiseoperationsforoneormoreflightstomitigatetheeffectofthatdelay.6.5.22 Inpractice,thismeansthatratherthan integratingadepartureandsubsequentarrivalforoneflight, a departure at one airport may actually be integrated into an arrival stream 2 or 3 flightsdownstream.This is theultimategoalof tail tracking (managementofanairframeassociatedwithaseriesofflights).

Figure14:IntegrationofDeparturestoNextAirportArrivals

6.5.23 In the strategic timeframe, business rules are established formanaging aircraft through thesystem rather than individual flights. This requires close integration of intended business outcomes,prioritisationofcitypairs,etc.Becausethemanagementprocessextendsacrossaseriesofairports,theCDMprocess isnecessarilymore complex than layer2activities,andwillneed tobe supportedbyarangeofautomatedmodellinganddecisionsupporttools.6.5.24 The need to integrate CDM at several airports also means that managing system variables(weather,etc)becomesmorecomplex.Forthisreason,higherfidelitymanagementwillgenerallybeleftto thepretactical timeframewithsignificantoverlap into tactical.Thismeans thatwhilst individualflightswillbemanagedtactically,therewillbeasimultaneouspretacticalmanagementprocessrelatedtodownstream flightsbythesameaircraft. Inaddition,theposttactical flightanalysiswillbecomeasignificantinputtotacticalandpretacticalmanagementofdownstreamflights.


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Appendix1:CDMExtractfromtheICAOATMOperationalConcept10. COLLABORATIVEDECISIONMAKING810.1 CollaborativedecisionmakingwillallowallmembersoftheATMcommunity,especiallyairspaceusers,toparticipateintheATMdecisionmakingthataffectsthem.Thelevelofparticipationwillreflecttheleveltowhichadecisionwillaffectthem.10.2 Collaborativedecisionmakingwill apply to all layersofdecisions, from longertermplanning activitiesthroughtorealtimeoperations.ItwillapplyacrossallconceptcomponentsoftheATMsystemandisanessentialelementoftheoperationalconcept.10.3 Collaborativedecisionmakingmeansachievinganacceptablesolutionthattakesintoaccounttheneedsof those involved.Allparticipantswill therefore require a spiritof cooperation.Abalance is requiredbecausecollaborative decisionmaking is primarily invoked to resolve competing demands for anATM resource and toorganizeasafesharingofthatresourceamongairspaceusers.10.4 The time available for achieving a collaborative decision decreases from the strategic to the tacticalstages. In themost tactical of situations, theremay be no time to consider options; however,wherever suchsituations can be foreseen, collaborative decisionmakingwill have been previously used to determine agreedproceduresforsuchcases.Forexample,rulesfordeterminingprioritiesforaccessinganATMresourcewillhavebeencollaborativelyagreedinadvance.Thereforecollaborativedecisionmakingcanbeappliedbothactivelyand,throughagreedprocedures,passively.10.5 Effective informationmanagementandsharingwillenableeachmemberof theATMcommunity tobeaware, ina timelymanner,of theneeds, constraintsandprioritiesofothermembers in relation toadecisionmakingissue.10.6 Collaborativedecisionmaking canoccuramongairspaceusersdirectly,withoutany involvementofanATMserviceprovider.10.7 Wherea serviceprovider is involved incollaborativedecisionmakingbecauseofa requirementof theATMsystem,itisoftentheATMserviceproviderthatwillproposeasolutionforconsiderationbytheairspaceuserbecause the service providerwill be aware of the requirements of other users and service providers and thecollaboratively agreed rules for resolving competing requests for anATM resource.However, because it is aninformationrichenvironmentwhere theairspaceusermayhaveaccess to the same informationas the serviceprovider,theairspaceuserwillunderstandwhyaparticularsolutionhasbeenproposed.10.8 Iftimepermits,ausercanproposeanalternativesolutionthataddressesauserspreferencethatisnotknown to the service provider. In the sameway, the service provider can reject the users proposed solutionbecause of an ATM requirement that the user is not aware of. This illustrates how important full sharing ofappropriateinformationisinordertohavetimelycollaborativedecisionmaking.8GlobalAirTrafficManagementOperationalConceptICAODoc9854AppendixI

cdm operational concept

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