项目管理6

SchedulingResources1SessionOutcomes•Followingthesessionthedelegatesshouldhaveabasicunderstandingofthetypicalresourceschedulingproblemsfortimeaswellasresourcesconstrainedprojects.Inadditionthedelegateshouldbeabletoshowhowfreeslackcanbeusedtoeffectresourceleveling.SchedulingResources2PreambleSchedulingResources3TheResourceProblem•Afterstaffandotherresourceshavebeenallocatedtheprojectmanagerstillneedtoanswerthefollowingquestions:–Willtheresourcesbeadequateandavailablewhenneeded;–Willoutsidecontractorshavetobeused;–Willunforeseenresourcedependenciesexist–willtherebeanewcriticalpath;–Howmuchflexibilitydowehaveinusingresources;–Areoriginaldeadlinesrealistic.SchedulingResources4TheResourceProblem•ResourcesandPriorities:–Projectsequencingandschedulingdealspoorlywithresourceavailabilityandutilization;–Projectnetworktimesarenotascheduleuntilresourceshavebeenassigned:•Theimplicitassumptionisthatresourceswillbeavailableintherequiredamountswhenneeded;•Addingnewprojectsrequiresmakingrealisticjudgmentsofresourceavailabilityandprojectdurations;•Resourcesmaybeadequatebutdemandcanvary–thenresourcelevelingorsmoothingisrequired;or•Resourcesmaynotbeadequatetomeetpeakresourcerequirements,thelatestartdateofcertainactivitieswillhavetobedelayedandprojectdurationbeincreased–thisisreferredtoasresourceconstrainedscheduling.SchedulingResources5TypesofProjectConstraints•TechnicalorLogicConstraints:–Constraintsrelatedtothenetworkedsequenceinwhichprojectactivitiesmustoccur–example,digtrenches,pourcement,thenlaybricksforwalls…•PhysicalConstraints:–Activitiesthatcannotoccurinparallelorareaffectedbycontractualorenvironmentalconditions–shiprenovation,onepersonallowedinconfinedspace…•ResourceConstraints:–Theabsence,shortage,oruniqueinterrelationshipandinteractioncharacteristicsofresourcesthatrequireaparticularsequencingofprojectactivities-example,normallyyouhave3peopletodothreeactivitiesinparallel,butbecauseyouonlyhaveonepersonyouhavetoscheduletheminseries–NB!!Resourcedependencytakesprioritybutcannotviolatetechnicaldependencies.SchedulingResources6ConstraintExamplesSchedulingResources7KindsofResourceConstraints•People;•Materials;•Equipment;•WorkingCapital.SchedulingResources8ClassificationofASchedulingProblem•ClassificationofProblem:–Usingaprioritymatrixwillhelpdetermineiftheprojectistimeorresourceconstrained;•TimeConstrainedProject:–Aprojectthatmustbecompletedbyanimposeddate;•Timeisfixed,resourcesareflexible:additionalresourcesarerequiredtoensureprojectmeetsschedule•ResourceConstrainedProject:–Aprojectinwhichthelevelofresourcesavailablecannotbeexceeded:•Resourcesarefixed,timeisflexible:inadequateresourceswilldelaytheproject.SchedulingResources9ResourceAllocationMethods•Resourceallocationisbasedonthefollowingassumptions:–Splittingactivitiesisnotallowed—onceanactivityisstart,itiscarriedtocompletion;–Levelofresourceusedforanactivitycannotbechanged;–Activitieswiththemostslackposetheleastrisk;–Reductionofflexibilitydoesnotincreaserisk;–Thenatureofanactivity(easy,complex)doesn’tincreaserisk.SchedulingResources10ResourceAllocationMethods•Time-ConstrainedProjects:–Projectsthatmustbecompletedbyanimposeddate;–Requiretheuseoflevelingtechniquesthatfocusonbalancingorsmoothingresourcedemandbyusingpositiveslack(delayingnoncriticalactivities)tomanageresourceutilizationoverthedurationoftheprojectwiththefollowingresult:•Peakresourcedemandsarereduced;•Resourcedemandoverthelifeoftheprojectarereduced;•Fluctuationinresourcedemandisminimized.SchedulingResources11BotanicalGarden12345SchedulingResources12BotanicalGardenSchedulingResources13BotanicalGarden12345SchedulingResources14BotanicalGarden12345Usingtheslackofirrigationtostart3dayslateSchedulingResources15BotanicalGarden12345Usingtheslackoffenceandwallstostart3dayslateSchedulingResources16BotanicalGardenSchedulingResources17ResourceAllocationMethods•ResourceDemandLevelingTechniquesforTime-ConstrainedProjects:–Advantages:•Peakresourcedemandsarereduced;•Resourcesdemandoverthelifeoftheprojectarereduced;•Fluctuationinresourcedemandisminimized;–Disadvantages:•Lossofflexibilitythatoccursfromreducingslack;•Increasesinthecriticalityofallactivities.SchedulingResources18ResourceAllocationMethods•Resource-ConstrainedProjects:–Projectsthatinvolveresourcesthatarelimitedinquantityorbytheiravailability’–Schedulingofactivitiesrequirestheuseofheuristics(rules-of-thumb)thatfocuson:•Minimumslack;•Smallest(least)duration;•Lowestactivityidentificationnumber.–Theparallelmethodisusedtoapplyheuristics:•Aniterativeprocessthatstartsatthefirsttimeperiodoftheprojectandschedulesperiod-by-periodanyactivitiesscheduledtostartusingthethreepriorityrules.SchedulingResources19ResourceAllocationMethodsSchedulingResources20TheImpactsofResource-ConstrainedScheduling•Reducesdelaybutreducesflexibility;•Increasescriticalityofevents;•Increasesschedulingcomplexity;•Maymaketraditionalcriticalpathnolongermeaningful;•Canbreaksequenceofevents;•Maycauseparallelactivitiestobecomesequentialandcriticalactivitieswithslacktobecomenoncritical.bSchedulingResources21•