Time Management

Reference Material to study:

• A Guide to the Project Management Body of Knowledge, Chapter 6 (1996 edition)
• Project Planning, Scheduling & Control, Chapters 5-7, Lewis, James P., 1995
• Project Management, A Managerial Approach, Chapters 8-9, Meridith & Mantel
• The New Project Management, Chapter 9, Frame, J. Davidson, 1994
• PMP Challenge!, ESI, Time section
• PMBOK Q&A, PMI, Time section

What to Study?

• The PMBOK phases of Project Time Management: Activity Definition, Activity Sequencing, Activity Duration Estimating, Schedule Development, Schedule Control

(Be familiar with Inputs, Tools and Techniques, and Outputs for each phase)

• Be familiar with the different types of scheduling charts (Gantt, Milestone, Networking)
• Be familiar with the different techniques of networking (ADM, PDM, and PERT)
• Understand the concept of critical path and how to determine critical path.
• Know how to facilitate recovery through techniques such as crashing, fast tracking, managing slack and overtime.
• Understand how to calculate the Programmed Evaluation & Review Technique (PERT)
• Know the concept of the Schedule Performance Index (SPI) and how to calculate.
• Understand the logical relationships between tasks. (FS, FF, SS, SF and lag)
• Know what float is and how to determine.
• Know how to calculate Early Start, Early Finish, Late Start, and Late Finish.

Key Definitions

Activity: An element of work performed during the course of a project.
(Normally has duration, cost, and resource requirements.)

Baseline: The original plan plus or minus approved changes.

Arrow Diagram Method (ADM): A network diagramming technique in which activities are represented by arrows. The tail of the arrow represents the start and the head of the
arrow represents the end of the activity. Activities are connected at
points called nodes to illustrate the sequence in which activites are
expected to be performed. Also called Activity-On-Arrow (AOA).

Backward Pass: The calculation of late finish and start dates for the uncompleted portions
of all network activities. Determined by working backwards through the
network logic from the project's end date.

Concurrent Engineering: Generally speaking, an approach to project staffing that calls for the
implementors to be involved in the design phase. (sometimes confused with fast tracking.)

Crashing: Taking action to decrease the total project duration after analyzing a
number of alternatives to determine how to get the maximum duration compression for the least cost.

Critical Activity: An activity on a critical path.

Critical Path: The series of activities which determines the earliest completion of the
project. The critical path is usally defined as those activities with float
less than or equal to a specified value (usually zero).

Critical Path Method (CPM): A network analysis technique used to predict project duration by
analyzing which path has the least amount of scheduling flexibility.
Early dates are calculated using a forward pass; late dates are
calculated using a backwards pass.

Data Date (DD): The point in time that separates actual (historical) data from future
(scheduled) data. Also called as-of date.

Dummy Activity: An activity of zero duration used to show a logical relationship in the
arrow diagramming method. Dummy activities are used when logical
relationships cannot be completely or correctly described with regular
activity arrows. Dummies are shown graphically as a dashed line
headed by an arrow.

Duration (DU): The number of work periods (not including holidays and other non-working periods) required to complete an activity or other project element.

Early Finish Date (EF): In the critical path method, the earliest possible date in which the
uncompleted portions of an activity or project can complete. Can
change as the project progresses.

Early Start Date (ES): In the critical path method, the earliest possible date in which the
uncompleted portions of an activity or project can start Can change
as the project progresses.

Effort: The number of labor units required to complete an activity or other
project element. Should not be confused with duration.

Event-on-Node: A network diagramming technique in which events are represented by
boxes (or nodes) connected by arrows to show the sequence in which
the events are to occur.

Fast Tracking: Compressing the project schedule by overlapping activities that would
normally be done in sequence (such as design and construction).

Float: The amount of time that an activity may be delayed from its early
start without delaying the project finish date. (Also called slack, total
float, and path float).

Forward Pass: The calculation of the early start and early finish dates for the
uncompleted portions of all network activities.

Free Float (FF): The amount of time an activity can be delayed without delaying the
early start of any immediately succeeding activities.

Gantt Chart: A graphic display of schedule-related information using bars.

Hammock: An aggregate or summary activity.

Hanger: An unintended break in a network path. Hangers are usually caused by
missing activities or missing logical relationships.

Lag: A modification of a logical relationship which directs a delay in the successor task.

Late Finish Date (LF): In the critical path method, the latest possible date that an activity may be completed without delaying a specified milestone (usually the project finish date).

Late Start Date (SF): In the critical path method, the latest possible date that an activity may
begin without delaying a specified milestone (usually the project finish date).

Lead: A modification of a logical relationship which allows an acceleration of
the successor task. For example, in a FS relationship with a 10 day
lead, the successor can start 10 days prior to the completion of the
predecessor.

Level of Effort (LOE): Support type activity (e.g., vendor or customer liason) that does not
readily lend itself to measurement of discrete accomplishment.
Generally characterized by a uniform rate of activity over a specific period of time.

Logical Relationship: A dependency between two project activities or between an activity and
a milestone. Four possible types: FS, FF, SS, and SF. (see logical relationships under concepts).

Master Schedule: A summary level schedule which identifies the major activities and milestones.

Milestone: A significant event in the project, usually completion of a major
deliverable.

Milestone Schedule: A summary level schedule which identifies the major milestones.

Path Convergence: In mathematical analysis, the tendency of parallel paths of approximately
equal duration to delay the completion of the milestone where they
meet.

Precedence Diagram Method (PDM): A network diagramming technique in which activities are represented by nodes. Activities are linked by precedence relationships to show the
sequence in which the activiites are to be performed.

Program Evaluation and Review Technique (PERT): An event-oriented network analysis technique used to estimate project duration when there is a high degree of uncertainty with the individual
activity duration estimates.

Project Network Diagram: Any schematic display of the logical relationships of project activities.
Always drawn from left to right to reflect project chronology. Often incorrectly referred to as a "PERT chart".

Remaining Duration (RDU): The time needed to complete an activity.

Resource Leveling: Any form of network analysis in which start and finish dates are driven by resource management concerns.

Resource-Limited Schedule: A project schedule whose start and finish dates reflect expected
resource availability. The final project schedule should always be
resource limited.

Scheduled Finish Date (SF): The point in time work was scheduled to finish on an activity. The
scheduled finish date is normally within the range of dates delimited by
the early finish date and the late finish date.

Scheduled Start Date (SS): The point in time work was scheduled to start on an activity. The
scheduled start date is normally within the range of dates delimited by
the early start and late start dates.

Slack: Synonymous with float.

Time-Scaled Network Diagram: Any project network diagram drawn is such a way that the positioning
and length of the activity represents its duration. Essentially, it is a
bar chart that includes network logic.

Total Float: Synonymous with float.

Work Item: Synonymous with activity.

Time Management
Processes

Activity Definition:

• The process of identifying and documenting the specific activities that must be performed to produce the various project deliverables identified in the WBS.
• Define the activities such that the project objectives will be met.l,
• Inputs include: WBS, scope statement, historical information, constraints, and assumptions
• Methods used during activity definition:
  • Decomposition: Involves subdividing project elements into smaller, more manageable components. Differs from scope definition in that the outputs are activities (action steps) rather than deliverables
  • Templates: Activity lists or portions of activity lists from previous projects.
• Outputs include: Activity list, supporting detail including assumptions and constraints, and WBS updates
  

Activity Sequencing:

• The process of identifying and documenting interactivity dependencies.
• Activities must be sequenced accurately.
• Inputs include: Activity list, product description, mandatory dependencies, discretionary dependencies, external dependencies, constraints, and assumptions.
• Methods used during activity sequencing are: Precedence Diagramming Method, Arrow Diagramming Method, conditional diagramming methods, and network templates.
• Network templates can include an entire project or only a portion of it. (portions are referred to as subnets or fragnets.) Subnets are useful where a project inincludes several identical or nearly identical features such as floors on a high-rise office building or program modules on a software project.
• Outputs include: Project network diagram and activity list updates.

Activity Duration Estimating:

• The process of estimating the number of work periods needed to complete each identified activity.
• Inputs include: Activity list, constraints, assumptions, resource requirements, resource capabilities, and historical information. .
• Methods used during activity duration estimating include: expert judgment, analogous estimating (top-down estimating), and simulation.
• Outputs include: Activity duration estimates, basis of estimates, and activity list updates.

Schedule Development:

• The process of analyzing activity sequences, durations, and resource requirements to create the project schedule.
• Inputs include: Activity list, constraints, assumptions, resource requirements, resource capabilities, and historical information.
• The methods used in schedule development include: expert judgment, analogous estimating, and simulation.
• Outputs from schedule development: activity duration estimates, basis of estimates, and activity list updates.

Schedule Control:

• The process of controlling changes to the project schedule.
• Inputs include: Project schedule, performance reports, change requests, and schedule management plan.
• Methods for schedule control include: Schedule change control system, performance measurement, additional planning, and project management software.
• Outputs include: schedule updates, corrective action, and lessons learned.
  

Time Management
Concepts

Scheduling Charts:

• Gant:
  • Bar oriented
  • In pure form, a gant does not show task dependencies and relationships.
• Milestone:
  • Consumes no resources or duration.
  • Marks the start or finish of a significant event.
• Network:
  • Shows task relationships and dependencies.
  • Sometimes incorrectly referred to as a PERT chart.

Hard Coded Constraints:

• Must Start/Finish On
• Start No Earlier/Later Than
• Finish No Earlier/Later Than
• As soon as possible (ASAP) (Calculated using forward pass)
• As late as possible (ALAP) (Calculated using backwards pass)

Time Mgmt Concepts

Diagram Techniques:

Precedence diagram Method (PDM):

• Also called Activity on Node.
• Four types of logical relationships:
  • Finish to Start: The predecessor activity must finish before the successor activity can start.
  • Finish to Finish: The predecessor activity must finish before the successor activity can finish.
  • Start to Start: The predecessor activity must start before the successor activity can start.
  • Start to Finish: The predecessor activity must start before the successor activity can finish.
• Also can show lead or lag time.
• Lead is the same as negative lag.

Arrow Diagram Method (ADM):

• Also called Activity on Arrow
• Arrows represent activities while nodes represent the dependencies
• May require the use of dummy activities to define all logical relationships correctly
• Only shows "Finish to start" relationships

Conditional Diagramming Methods:

• GERT and System Dynamics models
• Allows for nonsequential activities such as loops or conditional branches

Sample Questions

1. During what Time Management Process are the specific activities that must be performed to produce the deliverables in the WBS identified and documented?

1. Activity Sequencing
2. Activity Definition
3. Schedule Development
4. Activity Duration Estimating

2. A period of time in work weeks which includes non-working days is called:

1. Elapsed Time
2. Duration
3. Effort
4. Earned Time

3. The amount of time that an activity can be delayed from its early start without delaying the project end date is called:

1. Negative Float
2. Free Float
3. Total Float
4. Float
5. c and d

4. What are you likely to see as a project progresses in a schedule with must fix dates and little or no slack?

1. Lots of free float
2. Idle resources
3. Negative float
4. Positive float

5. Given the following estimates: Optimistic 3 days, Pessimistic 9 days, and most likely 6 days, what is the PERT weighted average?

1. 6
2. 4
3. 6.3
4. 6.1
   

6. What is the standard deviation for the estimates in the above problem?

1. 0.6
2. 2
3. 1.5
4. 0.5
5. 1
   

7. In crashing the schedule, you would focus on:

1. Accelerating as many tasks as possible
2. Accelerating just the non-critical tasks
3. Accelerating the performance of tasks on the critical path
4. None of the above
   

8. To calculate the late start and late finish dates for a set of tasks, you must do:

1. An analysis of the critical path
2. A forwards pass
3. A backwards pass
4. a and c
5. all of the above

9. An activity that consumes no time or resources and shows only that a dependency exists between two activities is called:

1. A milestone
2. A hammock
3. A dummy activity
4. a and c
5. all of the above
   

10. A modification of a logical relationship that allows an acceleration of the successor task is represented by:

1. Lead time
2. Lag time
3. Negative Lag
4. a or b
5. a or c
   

11. Assuming a PERT weighted average computation, what is the probability of completing the project within plus-or-minus 3 standard deviations of the mean?

1. 68%
2. 99.74%
3. 95%
4. 75%
   

12. Schedule variance can be determined by:

1. BCWP - ACWP
2. ACWP - BCWP
3. EAC - ACWP
4. BCWP - BCWS
   

13. What is critical path?

1. The shortest path through the network, which represents the longest amount of time in which a project can be completed.
2. The path with zero float.
3. The longest path through the network, which represents the shortest amount of time in which a project can be completed.
4. The path with the most activities with the longest durations.
5. b and c
   

14. The Time Management Process that involves identifying and documenting interactivity dependencies is called:

1. Activity Definition
2. Activity Duration Estimating
3. Activity Dependencies
4. Activity Sequencing
   

15. A network diagram that uses nodes to represent activities and arrows to show the activity dependencies and allows no loops is called:

1. AOA
2. AON
3. ADM
4. GERT

Answers

1. B
2. A
3. E Free float is the amount of time an activity can be delayed without affecting the start time of the succeeding activity.
4. C
5. A
6. E
7. C
8. C
9. C ESI Questions, #23
10. E
11. B Lewis, pg. 181
12. D
13. E
14. D
15. B