工程管理专业英语专业版

9.1第一段Constructionplanningisafundamentalandchallengingactivityinthemanagementandexecutionofconstructionprojects.Itinvolvesthechoiceoftechnology,thedefinitionofworktasks,theestimationoftherequiredresourcesanddurationsforindividualtasks,andtheidentificationofanyinteractionsamongthedifferentworktasks.Agoodconstructionplanisthebasisfordevelopingthebudgetandthescheduleforwork.Developingtheconstructionplanisacriticaltaskinthemanagementofconstruction,eveniftheplanisnotwrittenorotherwiseformallyrecorded.Inadditiontothesetechnicalaspectsofconstructionplanning,itmayalsobenecessarytomakeorganizationaldecisionsabouttherelationshipsbetweenprojectparticipantsandevenwhichorganizationstoincludeinaproject.Forexample,theextentwhichsub-constructionwillbeusedonaprojectisoftendeterminedduringconstructionplanning.在施工项目的管理和执行中，施工计划是一项基本的并且具有挑战性的活动。它涉及到技术的选择，工作任务的定义、每一个任务所需资源和维持时间的估算，以及不同工作任务之间相互作用的识别等工作。一个好的施工计划是制定工作计划和工作进度的基础。确定施工计划是管理当中的一项重要工作，即使这个施工计划不是书面的或其他正式记录的形式。除了施工计划技术层面的问题之外，项目组织关于项目参与方之间的沟通和联系所作出的有管决策也是十分重要的。例如，分包商在一个项目中所承担的范围通常是在施工计划期间决定的。四Indevelopingaconstructionplan,itiscommontoadoptaprimaryemphasisoneithercostcontroloronschedulecontrolasillustratedinFig.9-1.Someprojectsareprimarilydividedintoexpensecategorieswithassociatedcosts.Inthesecases,constructionplanningiscostorexpenseoriented.Withinthecategoriesofexpenditure,adistinctionismadebetweencostsincurreddirectlyintheperformanceofanactivityandindirectlyfortheaccomplishmentoftheproject.Forexample,borrowingexpensesforprojectfinancingandProjectManagementforConstruction:ConstructionPlanningoverheaditemsarecommonlytreatedasindirectcosts.Forotherprojects,schedulingofworkactivitiesovertimeiscriticalandisemphasizedintheplanningprocess.Inthiscase,theplannerinsuresthattheproperprecenesamongactivitiesaremaintainedandthatefficientschedulingoftheavailableresourcesprevails.Traditionalschedulingproceduresemphasizethemaintenanceoftaskprecedences(resultingincriticalpathschedulingprocedures)orefficientuseofresourcesovertime(resultinginjobshopschedulingprocedures).Finally,mostcomplexprojectsrequireconsiderationofbothcostandschedulingovertime,sothatplanning,monitoringandrecordkeepingmustconsiderbothdimensions.Inthesecases,theintegrationofscheduleandbudgetinformationisamajorconcern.Inthischapter,weshallconsiderthefunctionalrequirementsforconstructionplanningsuchastechnologychoice,workbreakdown,andbudgeting.Constructionplanningisnotanactivitywhichisrestrictedtotheperiodaftertheawardofacontractforconstruction.Itshouldbeanessentialactivityduringthefacilitydesign.Also,ifproblemsariseduringconstruction,re-planningisrequired在制定一项施工计划时，通常在成本控制或进度控制中采用如图9-1所示的主要的重点。一些项目被主要地分为费用类别以及相关成本。在这些情况下，施工计划是成本或费用导向的。在划分支出类别时，我们将对执行一项活动所发生的直接成本和整个项目完成所需的间接成本予以特殊的对待。例如，为项目融资而产生的借款费用和日常开支项目通常被认为是间接成本。对其他项目来说，制定工作活动随时间的进度是重要的，而且在计划过程中被强调。在这种情况下，施工计划人员遇到的是确保维持各项工作适当的前导关系，保证对各项资源得到有效安排。传统的进度程序强调保持任务前导关系或资源随时间的有效利用。最后，大部分复杂的项目要求同时考虑成本和进度，所以计划、监控和记录必须考虑这两个尺度。在这些情况下，进度和预算信息的综合是一个重要的关注。9.4第四段Forgettinganecessaryprecedencerelationshipcanbemoreinsidious.Forexample,supposethatinstallationofdrywallshouldbedonepriortofloorfinishing.Ignoringthisprecedencerelationshipmayresultinbothactivitiesbeingscheduledatthesametime.Correctionsonthespotmayresultinincreasedcostsorproblemsofqualityinthecompletedproject.Unfortunately,therearefewwaysinwhichprecedenceomissionscanbefoundotherthanwithchecksbyknowledgeablemanagersorbycomparisontocomparableprojects.Oneotherpossiblebutlittleusedmechanismforcheckingprecedencesistoconductaphysicalorcomputerbasedsimulationoftheconstructionprocessandobserveanyproblems.忘记一个必要的先导关系会有隐伏的危害。例如，设想预制墙的安装应当在地板完成之前进行。忽视这个先导关系会导致这两项活动同时被安排。对这一点的更改会导致成本增加或已完成项目的质量问题。遗憾的是，除了依靠有经验的项目经理进行核对和通过与类似项目进行比较之外，还几乎没有能够发现工作之间先后顺序关系遗漏的有效方法。一种理论上可行但很少使用的核对先导关系的是对施工过程进行计算化的模拟，并从中观察和发现问题。第五段Finally,itisimportanttorealizethatdifferenttypesofprecedencerelationshipscanbedefinedandthateachhasdifferentimplicationsforthescheduleofactivities:●Someactivitieshaveanecessarytechnicalorphysicalrelationshipthatcannotbesuperseded.Forexample,concretepourscannotproceedbeforeformworkandreinforcementareinplace.●Someactivitieshaveanecessaryprecedencerelationshipoveracontinuousspaceratherthanasdiscreteworktaskrelationships.Forexample,formworkmaybeplacedinthefirstpartofanexcavationtrenchevenastheexcavationequipmentcontinuestoworkfurtheralonginthetrench.Formworkplacementcannotproceedfurtherthantheexcavation,butthetwoactivitiescanbestartedandstoppedindependentlywithinthisconstraint.●Someprecedencerelationshipsarenottechnicallynecessarybutareimposedduetoimplicitdecisionswithintheconstructionplan.Forexample,twoactivitiesmayrequirethesamepieceofequipmentsoaprecedencerelationshipmightbedefinedbetweenthetwotoinsurethattheyarenotscheduledforthesametimeperiod.Whichactivityisscheduledfirstisarbitrary.Asasecondexample,reversingthesequenceoftwoactivitiesmaybetechnicallypossiblebutmoreexpensive.Inthiscase,theprecedencerelationshipisnotphysicallynecessarybutonlyappliedtoreducecostsasperceivedatthetimeofscheduling.最后，还应当认识到，虽然我们定义了不同类型的先导关系，但每一种先导关系对于进度计划而言