Bài giảng Operations Management - Chapter 17: Project Management

Project ManagementMcGraw-Hill/Irwin Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.You should be able to:Discuss the behavioral aspects of projects in terms of project personnel and the project managerExplain the nature and importance of a work breakdown structure in project managementGive a general description of PERT/CPM techniquesConstruct simple network diagramsList the kinds of information that a PERT or CPM analysis can provideAnalyze networks with deterministic timesAnalyze networks with probabilistic timesDescribe activity ‘crashing’ and solve typical problems17-*Student SlidesProjectsUnique, one-time operations designed to accomplish a specific set of objectives in a limited time frameExamples:The Olympic GamesProducing a movieSoftware developmentProduct developmentERP implementation17-*Student SlidesWBSA hierarchical listing of what must be done during a projectEstablishes a logical framework for identifying the required activities for the projectIdentify the major elements of the projectIdentify the major supporting activities for each of the major elementsBreak down each major supporting activity into a list of the activities that will be needed to accomplish it17-*Student SlidesPERT (program evaluation and review technique) and CPM (critical path method) are two techniques used to manage large-scale projectsBy using PERT or CPM Managers can obtain:A graphical display of project activitiesAn estimate of how long the project will takeAn indication of which activities are most critical to timely project completionAn indication of how long any activity can be delayed without delaying the project17-*Student SlidesNetwork diagramDiagram of project activities that shows sequential relationships by use of arrows and nodesActivity on arrow (AOA)Network diagram convention in which arrows designate activitiesActivity on node (AON)Network convention in which nodes designate activitiesActivitiesProject steps that consume resources and/or timeEventsThe starting and finishing of activities17-*Student SlidesDeterministicTime estimates that are fairly certainProbabilisticTime estimates that allow for variation17-*Student SlidesFinding ES and EF involves a forward pass through the network diagramEarly start (ES)The earliest time an activity can startAssumes all preceding activities start as early as possibleFor nodes with one entering arrowES = EF of the entering arrowFor activities leaving nodes with multiple entering arrowsES = the largest of the largest entering EFEarly finish (EF)The earliest time an activity can finishEF = ES + t17-*Student SlidesFinding LS and LF involves a backward pass through the network diagramLate Start (LS)The latest time the activity can start and not delay the projectThe latest starting time for each activity is equal to its latest finishing time minus its expected duration:LS = LF - tLate Finish (LF)The latest time the activity can finish and not delay the projectFor nodes with one leaving arrow, LF for nodes entering that node equals the LS of the leaving arrowFor nodes with multiple leaving arrows, LF for arrows entering node equals the smallest of the leaving arrows17-*Student SlidesSlack can be computed one of two ways:Slack = LS – ESSlack = LF – EFCritical pathThe critical path is indicated by the activities with zero slack17-*Student SlidesThe beta distribution is generally used to describe the inherent variability in time estimatesThe probabilistic approach involves three time estimates:Optimistic time, (to)The length of time required under optimal conditionsPessimistic time, (tp)The length of time required under the worst conditionsMost likely time, (tm)The most probable length of time required17-*Student SlidesThe expected time, te ,for an activity is a weighted average of the three time estimates:The expected duration of a path is equal to the sum of the expected times of the activities on that path:17-*Student SlidesThe standard deviation of each activity’s time is estimated as one-sixth of the difference between the pessimistic and optimistic time estimates. The variance is the square of the standard deviation:Standard deviation of the expected time for the path17-*Student SlidesA project is not complete until all project activities are completeIt is risky to only consider the critical path when assessing the probability of completing a project within a specified time.To determine the probability of completing the project within a particular time frameCalculate the probability that each path in the project will be completed within the specified timeMultiply these probabilitiesThe result is the probability that the project will be completed within the specified time17-*Student SlidesProjects present both strategic opportunities and risksIt is critical to devote sufficient resources and attention to projectsProjects are often employed in situations that are characterized by significant uncertainties that demandCareful planningWise selection of project manager and teamMonitoring of the projectProject software can facilitate successful project completionBe careful to not focus on critical path activities to the exclusion of other activities that may become criticalIt is not uncommon for projects to failWhen that happens, it can be beneficial to examine the probable reasons for failureStudent Slides17-*