Bài giảng PMBOK - Chapter 5: Project Time Management

Chapter 5:Project Time Managementadopted from PMI’s PMBOK 2000 and Textbook : Information Technology Project Management (author : Dr. Kathy Schwalbe)1Contents of time managementdefinition: charter and scope statementsequence: mandatory dependencies, discretionary dependencies, external dependenciesschedule: ADM, PDMestimation: actual time + elapsed time. An art require experience. schedule development: Gantt chart, CPM and PERTschedule control and change control: perform checks, allow contingencies, communicate with stakeholders regularlyChapter 52Project Time ManagementDeveloping the schedule involves define the scope of the workdefine the activitiesestimate how long the activities will takedefine sequence the activities based on its relationshipsestimate associate costs with the activities. 3Project Time Management ProcessesProject time management involves the processes required to ensure timely completion of a project. 5 Processes include:Activity definitionActivity sequencing planningActivity duration estimatingSchedule developmentSchedule control controlChapter 54Activity Definition process4th planning phase processIt involves identifying and documenting the specific activities that must be performed in order to produce the deliverables and sub-deliverables identified in the WBS.5Inputs to Activity Definition processWBSThe primary input to Activity Definition. It is scope definition tool that organizes the work and provides a basis for project estimates.Scope statementmust be considered explicitly during Activity Definition. Project justification and objectives are especially important.Historical informationactivities required on similar projects should be considered in defining project activities.ConstraintsFactors that limit the team’s optionsAssumptionsfactors that, for planning purposes, will be considered to be true, real, or certain.Expert judgmentguided by historical information should be used whenever possible. subject-matter experts can help.6Tools & techniques for Activity Definition processProject schedules grow out of the basic document that initiate a projectProject charter includes start and end dates and budget informationScope statement and WBS help define what will be doneActivity definition involves developing a more detailed WBS and supporting explanations to understand all the work to be doneChapter 57Tools & techniques for Activity Definition process (2)Decompositiondividing project elements into smaller, more manageable components. Decomposition in Activity Definition and in Scope Definition differ; the final outputs in Activity Definition are activities (action steps) and deliverables (tangible items)Templatesprevious project templates help project team to jump-start the process.8Outputs from Activity Definition processActivity listincludes all activities that will be performed on the project. Descriptions of each activity should ensure that stakeholders understand how the work will be done.Supporting detailsincludes assumptions, constraints, and anything else that is relevant.WBS updateMissing deliverables, clarifications, or corrections. This output creates a feedback loop by which you get to tie up loose ends. Update the WBS and related documents, such as cost estimates. These updates are often called refinements.9Activity Sequencing5th planning phase process Involves reviewing activities and determining dependenciesMandatory dependencies: inherent in the nature of the work; hard logicDiscretionary dependencies: defined by the project team; soft logicExternal dependencies: involve relationships between project and non-project activities You must determine dependencies in order to use critical path analysisChapter 510Inputs to Activity SequencingActivities listincludes all activities that will be performed on the project.Product descriptionproduct characteristics. These often affect Activity Sequencing.Mandatory dependenciesinherent in the nature of the work being done. They often involve physical limitations. Constraints caused by mandatory dependencies are call hard-logic.Discretionary dependenciesdefined by the project management team. Constraints caused by discretionary dependencies are called soft logic.External dependenciesinvolve a relationship between project and non-project activities.Milestones part of activity sequencing to ensure that requirement for the milestone events are being met.11Tools & techniquesProject network diagrams a schematic display of the logical relationships among, or sequencing of, project activitiespreferred technique for showing activity sequencingPrecedence Diagramming Method (PDM)constructing a project network diagram to president the activities and connecting them with arrows to show the dependencies between tasks.Activities are represented by boxes, arrows show relationships between activitiesThis charting method is also called activities-on-node (AON)More popular than ADM method and used by project management software such as MS-project. better at showing different types of dependenciesThere are 4 types of dependencies: finish-to-start; finish-to-finish; start-to-start; start-to-finish. 12Tools & techniques (2)Arrow diagramming method (ADM)constructing a project network diagram by using arrows to represent the activities and connecting them at nodes to show the dependencies. Nodes or circles are the starting and ending points of activitiesIt is known as activities-on-arrow (AOA). This method uses only finish-to-start activities. Conditional diagramming methodsallow for non-sequential activities such as loops or conditional branches, neither of which is possible in the PDM or ADM.Network templatesCan expedite the preparation of project network diagrams13PDM fundamentals14Task Dependency Types in PDMChapter 515Sample Precedence Diagramming Method (PDM) Network Diagram for Project XProject 98 file16AOAfundamentals17Sample Activity-on-Arrow (AOA) Network Diagram for Project XChapter 518Steps for Creating AOA Diagrams1. Find all of the activities that start at node 1. Draw their finish nodes and draw arrows between node 1 and those finish nodes. Put the activity letter or name and duration estimate on the associated arrow 2. Continuing drawing the network diagram, working from left to right. Look for bursts and merges. Bursts occur when a single node is followed by two or more activities. A merge occurs when two or more nodes precede a single node3. Continue drawing the project network diagram until all activities are included on the diagram that have dependencies4. As a rule of thumb, all arrowheads should face toward the right, and no arrows should cross on an AOA network diagramChapter 519Outputs from Activity SequencingProject network diagrama schematic delay of the project’s activities and the logical relationships (dependencies) among them. (note: it is not called a PERT chart)Activity list updateallow a feedback loop if a network diagram reveals instances where an activity must be redefined in order to diagram the correct logical relationships20Activity Duration Estimating6th of 21 planning phase processAfter defining activities and determining their sequence, the next step in time management is duration estimating Duration includes the actual amount of time worked on an activity plus elapsed timePeople doing the work should help create estimates, and an expert should review themChapter 521Inputs to Activity Duration Estimation Activity listincludes all activities that will be performed on the project.ConstraintsFactors that limit the performance of the project. When constraint are involved, special considerations are often required for communications.AssumptionsFactors that for planning purposes are considered to be true, real, or certain.Resource requirementscontrolling factors on activities duration. The duration of most activities will be significantly influenced by the resources assigned to them.Resource capabilitiesstaff and material resources assigned to them will affect the duration of most activities.Historical informationmay be available for review from project records, commercial duration-estimating databases, and team knowledge.22Tools & techniquesExpert judgmentJudgment guided by historical information should be used whenever possible. An example is the Delphi Technique, which is a forecasting technique that relies on gathering expert opinions. After several iterations, the experts reach consensus of opinions.Analogous estimatinguses the duration of a previous, similar activity as the basis for estimating the duration of a future activity.It is also called top-down estimating.Simulationcalculates multiple durations with different sets of assumptions. The most common is the Monte Carlo Analysis.23Outputs from Activity Duration Estimation Activities duration estimationQuantitative assessments of the likely number of work periods – such as hours, days, weeks, or months – that will be required to complete an activities.Basis of estimatesincludes the assumptions made in developing your estimates, which must be documented.Activities list updatesthis feedback loop ensures completeness.24Gantt ChartsGantt charts provide a standard format for displaying project schedule information by listing project activities and their corresponding start and finish dates in a calendar formatSymbols include:A black diamond: milestones or significant events on a project with zero durationThick black bars: summary tasksLighter horizontal bars: tasksArrows: dependencies between tasksChapter 525Schedule development7th of 21 planning phase processIt is the process of determining the start and finish dates for all project activitiesThe activity sequences, activity duration, and resource requirement are analyzed together to create the project schedule.26Schedule Development7th of 21 planning phase processSchedule development uses results of the other time management processes to determine the start and end date of the project and its activitiesUltimate goal is to create a realistic project schedule that provides a basis for monitoring project progress for the time dimension of the projectImportant tools and techniques include Gantt charts, PERT analysis, critical path analysis, and critical chain schedulingChapter 527Inputs to Schedule developmentProject network diagram: A schematic display of the project’s activities and the logical relationships (dependencies) among them.Activities duration estimation: Quantitative assessments of the likely number of work periods – such as hours, days, weeks, or months – that will be required to complete an activities.Resource requirements: define what physical resources (people, equipment, and materials) and what quantities of each are needed to perform project activities.Resource pool descriptions: identify the required resources, listing who will be available, when, and in what patterns, as necessary for schedule development.28Inputs to Schedule development (2)Calendars: identify the time when work is allowed. Project calendars affect all resource. Resource calendars affect a specific resource or category of resource.Constraints: constraints to consider during schedule development include: a) imposed dates; b) key events or major milestones.Assumptions: factors that, for planning purposes, are considered to be true, real, or certain.Leads and lags: the lead is the minimum necessary lapse of time between the start of one activity and the start of an overlapping activity. The lag is the waiting time between two tasks (negative lead) such as waiting for concrete to harden or paint to dry.29Inputs to Schedule development (3)Risk management plan: A subsidiary part of the project plan. It documents the procedures to manage risk throughput the project. Activity attributes: describes various characteristics of the activities scheduled – responsibilities, WBS order, the location where the work will be performed, the level. 30Tools & techniquesMathematical analysisCalculating theoretical early and late start and finish dates for all project activities without any resource pool limitations. The most common analysis techniques are Critical path method (CPM); Graphical evaluation and review technique (GERT);PERT.Duration compression methodsways to shorten the project schedule without changing the project scope. Two techniques are used: crashing; fast-tracking.31Tools & techniques (2)Simulation: calculates multiple durations with different sets of assumptions. The most common is Monte Carlo analysis, in which a distribution of probable results is defined for each activity and used to calculate a distribution of probable results for the total project.Resource level heuristicsuse mathematical analysis to produce a preliminary schedule. Resource leveling heuristics are used when the schedule requires more resources during certain time periods than are available, or requires changes in resource level that are not manageable.Project management softwarewidely used to assist with schedule development32Outputs from Schedule development Project scheduleincludes at a minimum the planned start and expected finish dates for each detailed activity. displayed graphically in one of the following formatsproject network diagrams (e.g. Gantt Chart)bar chartsmilestone chartsSupport detailsinclude at least documentation of all identified assumptions and constrains. Some examples are resource histograms, alternative schedules, and cash-flow schedules.Schedule management plandefines how changes to the schedules will be managed.Resource requirement updatesa result of resource leveling and activity list updates. 33Gantt Chart for Project XProject 98 fileChapter 534Gantt Chart for Software Launch ProjectProject 98 file35Sample Tracking Gantt ChartProject 98 filewhite diamond: slipped milestonetwo bars: planned and actual timesChapter 536Critical Path Method (CPM)CPM is a project network analysis technique used to predict total project durationA critical path for a project is the series of activities that determines the earliest time by which the project can be completedThe critical path is the longest path through the network diagram and has the least amount of slack or floatChapter 537Finding the Critical PathFirst develop a good project network diagramAdd the durations for all activities on each path through the project network diagramThe longest path is the critical pathChapter 538Simple Example of Determining the Critical PathConsider the following project network diagram. Assume all times are in days.How many paths are on this network diagram?How long is each path?Which is the critical path?What is the shortest amount of time needed to complete this project?Chapter 539Determining the Critical Path for Project X40More on the Critical PathIf one of more activities on the critical path takes longer than planned, the whole project schedule will slip unless corrective action is takenMisconceptions:The critical path is not the one with all the critical activities; it only accounts for timeThere can be more than one critical path if the lengths of two or more paths are the sameThe critical path can change as the project progressesChapter 541Using Critical Path Analysis to Make Schedule Trade-offsKnowing the critical path helps you make schedule trade-offsFree slack or free float is the amount of time an activity can be delayed without delaying the early start of any immediately following activitiesTotal slack or total float is the amount of time an activity may be delayed from its early start without delaying the planned project finish dateChapter 542Free and Total Float or Slack for Project X43Techniques for Shortening a Project ScheduleShortening durations of critical tasks for adding more resources or changing their scopeCrashing tasks by obtaining the greatest amount of schedule compression for the least incremental costFast tracking tasks by doing them in parallel or overlapping themChapter 544Importance of Updating Critical Path DataIt is important to update project schedule informationThe critical path may change as you enter actual start and finish datesIf you know the project completion date will slip, negotiate with the project sponsorChapter 545Multitasking Example46Program Evaluation and Review Technique (PERT)PERT is a network analysis techniqueto estimate project duration when there is a high degree of uncertainty about the individual activity duration estimatesPERT uses probabilistic time estimates based on different estimates of activity durationsoptimistic estimates (weighting 1)most likely estimates (weighting 4)pessimistic estimates (weighting 1)Chapter 547PERT Formula and ExamplePERT weighted average formula: optimistic time + 4x most likely time + pessimistic time 6Example:PERT weighted average = 8 workdays + 4 X 10 workdays + 24 workdays = 12 days 6where 8 = optimistic time, 10 = most likely time, and 24 = pessimistic time48Controlling Changes to the Project Schedule4th of 8 Controlling phase process It involves managing changes to the schedule. The major activities include monitor the schedule performance of project activities detect variances from the original schedule baseline. general steps:Perform reality checks on schedulesAllow for contingenciesDon’t plan for everyone to work at 100% capacity all the timeHold progress meetings with stakeholders and be clear and honest in communicating schedule issuesChapter 549Inputs to Schedule control Project scheduleAs a part of the integrated project plan, the approved schedule is called schedule baseline. Project team/manager re-baseline when the schedule becomes unrealistic. Re-baselining occurs when project team/manager do any major update in order to have a better control the schedule.Performance reportsprovide information on schedule execution – showing if planned dates have been met. These reports also alert project team on issues that may cause problem in future.Change requestsany update of schedule, that may require extending or accelerating the schedule.Scope management plandescribes how changes will be integrated into the project. It is part of the project plan.50Tools & techniques for Schedule control processSchedule change control system: defines the procedures for changing the project schedule. It includes the paperwork, tracking systems, and approval levels necessary for authorizing changes.Performance measurement techniques: assess the magnitude of any variations that occur in project performance. An important part of Schedule Control is to decide if the schedule variation requires corrective action.Additional planning: prospective changes may require new or revised activity duration estimates, modified activity sequences, or analysis of alternative schedules.Project management software: widely used to assist with schedule development and control. In the context of controlling, it is schedule tracking, and reporting. It helps levels resources, for schedule alternatives.51Using Software to Assist in Time ManagementSoftware for facilitating communications helps people exchange schedule-related informationDecision support models help analyze trade-offs that can be madeProject management software can help in various time management areas Chapter 552Outputs from schedule control processSchedule updates: include any modification to the schedule used to manage the project. A special category of schedule updates, revisions, describes changes to start and finish dates in the approval project schedule.Corrective action: encompasses anything that brings your expected future schedule back in line with the project plan. These actions are outputs from the other knowledge areas.Lessons learned: document causes of variances, the reasoning behind corrective actions, and other lessons learned from schedule change.53Working with People IssuesStrong leadership helps projects succeed more than good PERT chartsProject managers should useempowermentincentivesdisciplinenegotiationChapter 554Summaryimpo