Chapter 5 - Project time management. After reading this chapter, you will be able to: Understand the importance of project schedules and good project time management, discuss the process of planning schedule management, define activities as the basis for developing project schedules, describe how project managers use network diagrams and dependencies to assist in activity sequencing,...
Trang 1Chapter 5:
Project Time Management
adopted from PMI’s PMBOK 2000 and Textbook : Information Technology Project Management
(author : Dr. Kathy Schwalbe)
Trang 2Contents of time management
• definition: charter and scope statement
• sequence: mandatory dependencies, discretionary dependencies, external dependencies
Trang 3– estimate associate costs with the activities.
Trang 4Project Time Management
Processes
• Project time management involves the processes required to ensure timely completion of a
Trang 5Activity Definition process
• 4th planning phase process
• It involves identifying and documenting the specific activities that must be
performed in order to produce the
deliverables and subdeliverables
identified in the WBS.
Trang 6• Constraints
– Factors that limit the team’s options
• Assumptions
– factors that, for planning purposes, will be considered to be true, real, or certain.
• Expert judgment
– guided by historical information should be used whenever possible. subjectmatter experts can help.
Trang 7– Scope statement and WBS help define what
will be done
• Activity definition involves developing a more detailed WBS and supporting
explanations to understand all the work to
be done
Chapter 5
Trang 8steps) and deliverables (tangible items)
• Templates
– previous project templates help project team to jumpstart the process
Trang 9– Update the WBS and related documents, such as cost estimates. These updates are often called refinements.
Trang 10– Discretionary dependencies: defined by the project team; soft logic
– External dependencies: involve relationships between project and nonproject activities
• You must determine dependencies in order to use
critical path analysis
Chapter 5
Trang 12Tools & techniques
• Project network diagrams
– a schematic display of the logical relationships among, or sequencing of, project activities
– preferred technique for showing activity sequencing
• Precedence Diagramming Method (PDM)
– constructing a project network diagram to president the activities and connecting them with arrows to show the dependencies between tasks.
Trang 13– Nodes or circles are the starting and ending points of activities – It is known as activitiesonarrow (AOA). This method uses only finishtostart activities.
• Conditional diagramming methods
– allow for nonsequential activities such as loops or conditional branches, neither of which is possible in the PDM or ADM.
• Network templates
– Can expedite the preparation of project network diagrams
Trang 14fundamentals
Trang 15Chapter 5
Trang 16Sample Precedence Diagramming Method (PDM)
Network Diagram for Project X
Project 98 file
Trang 17fundamentals
Trang 18Sample ActivityonArrow (AOA) Network Diagram for Project X
Chapter 5
Trang 19Steps for Creating AOA Diagrams
1. 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
4. As a rule of thumb, all arrowheads should face toward the right, and
no arrows should cross on an AOA network diagram
Chapter 5
Trang 20• Activity list update
– allow a feedback loop if a network diagram reveals instances where an activity must be redefined in order
to diagram the correct logical relationships
Trang 21Activity Duration Estimating
• After defining activities and determining their sequence, the next step in time
Trang 22• Historical information
– may be available for review from project records, commercial duration
estimating databases, and team knowledge.
Trang 23• Analogous estimating
– uses the duration of a previous, similar activity as the basis for estimating the duration of a future activity.
– It is also called topdown estimating.
• Simulation
– calculates multiple durations with different sets of assumptions. – The most common is the Monte Carlo Analysis.
Trang 25Gantt Charts
• Gantt charts provide a standard format for
displaying project schedule information by listing project activities and their corresponding start and finish dates in a calendar format
• Symbols include:
– A black diamond: milestones or significant events on a project with zero duration
– Thick black bars: summary tasks
– Lighter horizontal bars: tasks
– Arrows: dependencies between tasks
Chapter 5
Trang 26Schedule development
• 7th of 21 planning phase process
• It is the process of determining the start and finish dates for all project activities
• The activity sequences, activity duration, and resource requirement are analyzed together to create the project schedule.
Trang 27Schedule Development
• 7th of 21 planning phase process
• Schedule development uses results of the other time management processes to determine the start and end date of the project and its activities
Chapter 5
Trang 28• Resource pool descriptions: identify the required
resources, listing who will be available, when, and in
what patterns, as necessary for schedule development
Trang 29Inputs 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
Trang 30Inputs 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.
Trang 31Tools & techniques
• Mathematical analysis
– Calculating theoretical early and late start and finish dates for all project activities without any resource pool limitations.
– Two techniques are used:
• crashing;
• fasttracking.
Trang 32Tools & 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 heuristics
– use 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 software
– widely used to assist with schedule development
Trang 33• Schedule management plan
– defines how changes to the schedules will be managed.
• Resource requirement updates
– a result of resource leveling and activity list updates.
Trang 34Gantt Chart for Project X
Project 98 file
Chapter 5
Trang 35Gantt Chart for Software Launch Project
Project 98 file
Trang 36Sample Tracking Gantt Chart
Project 98 file white diamond: slipped milestonetwo bars: planned and actual times
Chapter 5
Trang 37Critical Path Method (CPM)
• CPM is a project network analysis technique used to predict total project duration
Trang 38• The longest path is the critical path
Chapter 5
Trang 40Determining the Critical Path
for Project X
Trang 41More on the Critical Path
• If one of more activities on the critical path takes longer than planned, the whole project schedule
Trang 42Using Critical Path Analysis to
Make Schedule Tradeoffs
• Knowing the critical path helps you make schedule tradeoffs
• Free slack or free float is the amount of time an
activity can be delayed without delaying the early start of any immediately following activities
• Total slack or total float is the amount of time an
activity may be delayed from its early start without delaying the planned project finish date
Chapter 5
Trang 43Free and Total Float or Slack for
Project X
Trang 44Techniques for Shortening a
Project Schedule
• Shortening durations of critical tasks for adding more resources or changing their scope
Trang 45Importance of Updating Critical
Path Data
• It is important to update project schedule information
• The critical path may change as you enter actual start and finish dates
• If you know the project completion date
will slip, negotiate with the project sponsor
Chapter 5
Trang 46Multitasking Example
Trang 47– optimistic estimates (weighting 1)
– most likely estimates (weighting 4)
– pessimistic estimates (weighting 1)
Chapter 5
Trang 48and 24 = pessimistic time
Trang 49• Perform reality checks on schedules
– Allow for contingencies
– Don’t plan for everyone to work at 100% capacity all the time
– Hold progress meetings with stakeholders and be clear and honest in communicating schedule issuesChapter 5
Trang 50Inputs to Schedule control
• Project schedule
– As a part of the integrated project plan, the approved schedule is called schedule baseline.
• Change requests
– any update of schedule, that may require extending or accelerating the schedule.
• Scope management plan
– describes how changes will be integrated into the project. It is part of the project plan.
Trang 52Using Software to Assist in
Time Management
• Software for facilitating communications helps people exchange schedulerelated information
• Decision support models help analyze
tradeoffs that can be made
• Project management software can help in various time management areas
Chapter 5
Trang 53• 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.
Trang 54Working with People Issues
• Strong leadership helps projects succeed more than good PERT charts
Trang 55Summary
• importance of project schedules: IT project always overrun
Trang 56Summary (2)
• definition: charter and scope statement
• sequence: mandatory dependencies, discretionary dependencies, external dependencies