Chapter 2: Project Time Management

Transcription

1 Chapter 2: Project Time Management

2 Learning Objectives o o o o Understand the importance of project schedules and good project time management. Define activities as the basis for developing project schedules. Describe how project managers use network diagrams and dependencies to assist in activity sequencing. Understand the relationship between estimating resources and project schedules.

3 Learning Objectives (Cont.) o Explain how various tools and techniques help project managers perform activity duration estimating. o Use a Gantt chart for planning and tracking schedule information, find the critical path for a project, and describe how critical chain scheduling affect schedule development. o Discuss how reality checks and people issues are involved in controlling and managing changes to the project schedule.

4 Importance of Project Schedules o Managers often cite delivering projects on time as one of their biggest challenges. o Fifty percent of IT projects were challenged in the 2005 CHAOS study, and their average time overrun increased to 82 percent from a low of 63 percent in 2002.* o Schedule issues are the main reason for conflicts on projects, especially during the second half of projects. o Time has the least amount of flexibility; it passes no matter what happens on a project. *The Standish Group, Latest Standish Group CHAOS Report Shows Project Success Rates Have Improved by 50%, ( (March 25, 2005).

5 Conflict Intensity Over the Life of a Project Conflict Intensity Average Total Conflict Schedules Priorities Manpower Technical opinions Procedures Cost Personality conflicts Project Formation Early Phases Middle Phases End Phases

6 Individual Work Styles and Cultural Differences Cause Schedule Conflicts o Some people prefer to follow schedules and meet deadlines while others do not. o Different cultures and even entire countries have different attitudes about schedules.

7 Project Time Management Processes o Activity definition: Identifying the specific activities that the project team members and stakeholders must perform to produce the project deliverables. o Activity sequencing: Identifying and documenting the relationships between project activities. o Activity resource estimating: Estimating how many resources a project team should use to perform project activities.

8 Project Time Management Processes (Cont.) o Activity duration estimating: Estimating the number of work periods that are needed to complete individual activities. o Schedule development: Analyzing activity sequences, activity resource estimates, and activity duration estimates to create the project schedule. o Schedule control: Controlling and managing changes to the project schedule.

9 Activity Definition o An activity or task is an element of work normally found on the WBS that has an expected duration, a cost, and resource requirements. o Project schedules grow out of the basic documents that initiate a project. The project charter includes start and end dates and budget information. The scope statement and WBS help define what will be done. o Activity definition involves developing a more detailed WBS and supporting explanations to understand all the work to be done, so you can develop realistic cost and duration estimates.

10 Activity Lists and Attributes o An activity list is a tabulation of activities to be included on a project schedule. The list should include: The activity name An activity identifier or number A brief description of the activity o Activity attributes provide more information about each activity, such as predecessors, successors, logical relationships, leads and lags, resource requirements, constraints, imposed dates, and assumptions related to the activity.

11 Milestones o A milestone is a significant event that normally has no duration. o It often takes several activities and a lot of work to complete a milestone. o Milestones are useful tools for setting schedule goals and monitoring progress. o Examples include completion and customer signoff on key documents and completion of specific products.

12 Activity Sequencing o Involves reviewing activities and determining dependencies. Mandatory dependencies: Inherent in the nature of the work being performed on a project; sometimes referred to as hard logic. Discretionary dependencies:defined by the project team; sometimes referred to as soft logic. External dependencies: Involve relationships between project and non-project activities. o You must determine dependencies in order to use critical path analysis.

13 Project Network Diagrams o Project network diagrams are the preferred technique for showing activity sequencing. o A project network diagram is a schematic display of the logical relationships among, or sequencing of, project activities.

14 Network Planning Models CPM (Critical Path Method) Activity-on-Node Networks Do B Do A Do D Do C Activity-on-Arrow Networks Do A Do B Do C Do D

15 Sample Activity-on-Arrow (AOA) Network Diagram for Project X

16 Activity-on-Node Network o A project network should have only one start node. o A project network should have only one end node. o A node has a duration. A node represents an activity and activities take time to execute. o Links normally have no duration. Links represent the relationships between activities. o Precedents are the immediate preceding activities.

17 Activity-on-Node Network (Cont.) o Time moves from left to right. o A network may not contain loops. A loop is an error in that it represents a situation that cannot occur in practice. o A network should not contain dangles. o Representing lagged activities. o Labeling conventions.

18 Activity-on-Node Network (Cont.) Activity label duration ES LS Activity description EF LF Activity span Float

19 Activity-on-Node Network (Cont.) Earliest start Activity Latest finish Latest start Earliest finish

20 Activity-on-Node Network (Cont.) o The forward pass The forward pass is carried out to calculate the earliest dates on which each activity may be started and completed. Earliest start (ES) Earliest finish (EF) = ES + duration o The backward pass The backward pass is carried out to calculate the latest date at which each activity may be started and finished without delaying the end date of the project. Latest finish (LF) Latest start = LF duration

21 Activity-on-Node Network (Cont.) o Critical Path There will be at least one path through the network that defines the duration of the project. Any delay to any activity on this critical path will delay the completion of the project. Float is a measure of how much the start or completion of an activity may be delayed with effecting the end date of the project. Any activity with a float of zero is critical in the sense that any delay in carrying out the activity will delay the completion date of the project as a whole. o Float = ES LS

22 Activity-on-Node Network (Cont.) o Critical Path (Cont.) In managing the project, we must pay particular attention to monitoring activities on the critical path so that the effects of any delay or resource unavailability are detected and corrected at the earliest opportunity. Activity span is a measure of the maximum time allowable for the activity. o Activity span = ES LF

23 Activity-on-Node Network (Cont.) o Activity float Although the total float is shown for each activity, it really belongs to a path through the network. o Shortening the project duration If we wish to shorten the overall duration of a project we would normally consider attempting to reduce activity durations. In many cases this can be done by applying more resources to the task working overtime or procuring additional staff.

24 Activity-on-Node Network (Cont.) o Identifying critical activities The critical path identifies those activities which are critical to the end date of the project, however, activities that are not on the critical path may become critical. As the project proceeds, activities will invariably use up some of their float and this will require a periodic recalculation of the network. As soon as the activities along a particular path use up their total float then that path will become a critical path and a number of non-critical activities will suddenly become critical.

25 Activity Resource Estimating o Before estimating activity durations, you must have a good idea of the quantity and type of resources that will be assigned to each activity. o Consider important issues in estimating resources: How difficult will it be to complete specific activities on this project? What is the organization s history in doing similar activities? Are the required resources available?

26 Activity Duration Estimating o Duration includes the actual amount of time worked on an activity plus the elapsed time. o Effort is the number of workdays or work hours required to complete a task. o Effort does not normally equal duration. o People doing the work should help create estimates, and an expert should review them.

27 Schedule Development o Uses results of the other time management processes to determine the start and end dates of the project. o Ultimate goal is to create a realistic project schedule that provides a basis for monitoring project progress for the time dimension of the project. o Important tools and techniques include Gantt charts, critical path analysis, critical chain scheduling, and PERT analysis.

28 Gantt Charts o 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. o Symbols include: Black diamonds: Milestones Thick black bars: Summary tasks Lighter horizontal bars: Durations of tasks Arrows: Dependencies between tasks

29 Gantt Chart for Software Launch Project

30 Adding Milestones to Gantt Charts o Many people like to focus on meeting milestones, especially for large projects. o Milestones emphasize important events or accomplishments in projects. o You typically create milestone by entering tasks that have a zero duration, or you can mark any task as a milestone.

31 SMART Criteria o Milestones should be: Specific Measurable Assignable Realistic Time-framed

32 Sample Tracking Gantt Chart

33 Techniques for Shortening a Project Schedule o Three main techniques for shortening schedules: Shortening the duration of critical activities or tasks by adding more resources or changing their scope. Crashing activities by obtaining the greatest amount of schedule compression for the least incremental cost. Fast tracking activities by doing them in parallel or overlapping them.

34 Crashing and Fast Tracking Original schedule Shortened duration thru crashing Overlapped Tasks or fast tracking

35 Many Horror Stories Related to Project Schedules o Creating realistic schedules and sticking to them is a key challenge of project management. o Crashing and fast tracking often cause more problems, resulting in longer schedules. o Organizational issues often cause schedule problems.

36 Importance of Updating Critical Path Data o It is important to update project schedule information to meet time goals for a project. o The critical path may change as you enter actual start and finish dates. o If you know the project completion date will slip, negotiate with the project sponsor.

37 Schedule Control o Perform reality checks on schedules. o Allow for contingencies. o Don t plan for everyone to work at 100 percent capacity all the time. o Hold progress meetings with stakeholders and be clear and honest in communicating schedule issues.

38 Reality Checks on Scheduling o Review the draft schedule or estimated completion date in the project charter. o Prepare a more detailed schedule with the project team. o Make sure the schedule is realistic and followed. o Alert top management well in advance if there are schedule problems.

39 Working with People Issues o Strong leadership helps projects succeed more than good network planning charts. o Project managers should use Empowerment Incentives Discipline Negotiation

40 Summary o Project time management is often cited as the main source of conflict on projects, and most IT projects exceed time estimates. o Main processes include: Activity definition Activity sequencing Activity resource estimating Activity duration estimating Schedule development Schedule control

41 Questions and Answers