2. Project Time Management
Definition
Project Time Management includes the processes required to
accomplish timely completion of the project. The Project Time
Management processes include the following:
• Activity Definition – identifying and documenting specific schedule
activities that need to be performed to produce the various project
deliverables identified in the WBS. Definition should be directed
towards fulfilling project objectives
• Activity Sequencing – identifying and documenting dependencies
among schedule activities.
• Activity Resource Estimating – estimating the type and quantities of
resources required to perform each schedule activity.
May 2011
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3. Project Time Management
Definition
• Activity Duration Estimating – estimating the number of work
periods that will be needed to complete individual schedule activities.
• Schedule Development – analyzing activity sequences, durations,
resource requirements, and schedule constraints to create the project
schedule.
• Schedule Control – controlling changes to the project schedule.
May 2011
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4. Activity Definition
• Activity Definition is the process of breaking down the work packages
from the WBS into individual activities that make up all the work of the
work package.
• It is part of the iterative process of further decomposing the WBS to a
manageable level.
• The key to Activity Definition is to identify all the tasks required to
produce the work packages (and ultimately the deliverables)
• Activity list should include every activity needed to complete the
work of the project, along with an identifier or code so that you can
track each activity independently.
• Milestone is a significant point or event in the project.
May 2011
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6. Activity Sequencing
Definition
• Activity Sequencing involves identifying and documenting
interactivity dependencies (Logical Relationships).
• Activities must be sequenced accurately in order to support later
development of a realistic and achievable schedule.
• Sequencing can be performed by using project management software
or by using manual techniques. Manual and automated techniques can
also be used in combination.
• First you need to identify the type of dependency, and then you need
to determine the specific relationship between the activities.
May 2011
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7. Activity Sequencing
Dependency - Categories
• Mandatory dependency (Hard Logic) is defined by the type of work
being performed, and one activity is dependent on another activity. For
example, a utility crew can ’t lay the cable for a new housing area until a
trench has been dug.
• Discretionary dependency (Preferred Logic, Preferential Logic, Soft
Logic) is usually process - or procedure - driven and may include best -
practice techniques. An example is a decision to require sign - off on
certain types of activities to conform to an established corporate
practice.
• External dependency is a relationship between a project task and
some factor outside the project that drives the scheduling of that task.
Installation of a new server depends on when the vendor can deliver the
equipment.
May 2011
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8. Activity Sequencing
Dependency - Logical Relationships
• A predecessor activity is one that comes before another activity
• A successor activity is one that comes after the activity in question
• Identifying the correct relationship between dependent activities is
critical to developing an accurate schedule.
May 2011
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9. Activity Sequencing
Dependency - Logical Relationships
• Finish-to-Start (FS) : The initiation of the successor activity depends
upon the completion of the predecessor activity.
• Finish-to-Finish (FF) : The completion of the successor activity
depends upon the completion of the predecessor activity.
• Start-to-Start (SS) : The initiation of the successor activity depends
upon the initiation of the predecessor activity.
• Start-to-Finish (SF) : The completion of the successor activity
depends upon the initiation of the predecessor activity.
May 2011
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10. Activity Sequencing
Network Diagram
It depicts the project activities and the interrelationships among these
activities. Shows how the project tasks will flow from beginning to end.
• Precedence Diagramming Method (PDM)
• Arrow Diagramming Method (ADM)
• Conditional Diagramming Methods (GERT)
May 2011
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11. Activity Sequencing
Network Diagram - PDM
• A method of constructing network diagram using nodes to represent
activities and arrows to indicate dependencies
• Also called Activity On Node (AON)
May 2011
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12. Activity Sequencing
Network Diagram - ADM
• A method of constructing a project network diagram using arrows to
represent the activities and connecting them at nodes to show the
dependencies.
• Also known as Activity-On-Arrow (AOA).
• ADM uses only finish-to-start dependencies and can require the use
of “dummy” relationships called dummy activities, which are shown as
dashed lines, to define other logical relationships correctly.
• Since dummy activities are not actual schedule activities they are
given a zero value duration.
Event Activity Event
May 2011
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14. Activity Resource Estimating
Definition
• Resource is “any factor, except time, required or consumed to
accomplish an activity. Any substantive requirement of an activity that
can be quantified and defined.”
• Estimating schedule activity resources involves determining what
resources (Persons, equipment, or materiel) and what quantities of each
resource will be used, and when each resource will be available to
perform project activities.
• The Activity Resource Estimating process is closely coordinated with
the Cost Estimating process
May 2011
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16. Activity Duration Estimating
Definition
• Activity Duration is the process of estimating the time to complete
each item on the activity list.
• This process requires that the amount of work effort required to
complete the schedule activity is estimated and the assumed amount of
resources to be applied to complete the schedule activity is estimated.
Then the number of work periods needed to complete the schedule
activity can be determined.
May 2011
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17. Activity Duration Estimating
Techniques - Analogous estimating
• Using the actual duration of a previous, similar schedule activity as
the basis for estimating the duration of a future schedule activity.
• It is frequently used to estimate project duration when there is a
limited amount of detailed information about the project.
• In the early phases of a project it uses historical information and
expert judgment.
• It is most reliable when the previous activities are similar in fact and
not just in appearance, and the project team members preparing the
estimates have the needed expertise.
• Also known as top-down estimating, it is typically the least accurate
means of obtaining an estimate.
May 2011
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18. Activity Duration Estimating
Techniques - Parametric estimating
• A quantitatively based estimating method that multiplies the quantity
of work by the rate.
• To apply quantitatively based durations, you must know the
productivity rate of the resource performing the task or have a company
or industry standard that can be applied to the task in question.
For example, if a typical cable crew can bury 5 miles of cable in a day, it
should take 10 days to bury 50 miles of cable.
May 2011
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19. Activity Duration Estimating
Techniques - PERT
• Program Evaluation and Review Technique (PERT) is a method that
the U.S. Navy developed in the 1950s for the Polaris Missile Program.
• Three point estimates used:
- Most likely(M) : Most likely duration of the schedule activity
- Optimistic(O) : Activity duration is based on a best-case scenario
- Pessimistic(P) : Activity duration is based on a worst-case scenario
• Estimating based on 3 formulas:
i. PERT Duration: T = (P + 4M + O)/6
ii. Standard Task Deviation: S = (P – O)/6
iii.Variance : V = S ² = [(P – O)/6]²
May 2011
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20. Activity Duration Estimating
Techniques – Bottom up estimating
• Involves estimating the durations of individual work items, then
summarizing or rolling-up the individual estimates to get a project
total.
• The accuracy of bottom-up estimating is driven by the size of the
individual work items: smaller work items increase accuracy.
• This is called definitive estimate
May 2011
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23. Schedule Development
Definition
• Project schedule development, an iterative process, determines
planned start and finish dates for project activities. The planned dates
for performing activities and the planned dates for meeting milestones.
• Schedule development can require that duration estimates and
resource estimates are reviewed and revised to create an approved
project schedule that can serve as a baseline against which progress can
be tracked.
• Schedule development continues throughout the project as work
progresses, the project management plan changes, and anticipated risk
events occur or disappear as new risks are identified.
May 2011
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24. Schedule Development
Techniques - Critical Path Method
• The Critical Path Method (CPM) calculates the theoretical early start
and finish dates, and late start and finish dates, for all schedule
activities without regard for any resource limitations.
- Early start (ES) is the earliest date an activity can begin, as
logically constrained by the network.
- Early finish (EF) is the earliest date an activity can finish, as
logically constrained by the network.
- Late finish (LF) is the latest date an activity can complete without
impacting the project end date.
- Late start (LS) is the latest date you can start an activity without
impacting the project end date.
• The critical path is the longest full path on the project and
determines the shortest time to complete the project.
May 2011
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25. Schedule Development
Techniques - Critical Path Method
• Free Slack (Float): The amount of time a task can be delayed without
delaying the early start date of its successor
• Total Slack (Float): the amount of time a task can be delayed without
delaying the project completion date. This is the key type of float.
• Float Formula = LS- ES or LF – EF
• Tasks on critical path have no slack or float
• 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.
• Lag: A modification of a logical relationship which allows a delay in
starting of the successor task. For Example, in a FS relationship with
a 4 day lag, the successor can start 4 days after the completion of the
predecessor. May 2011
Slide 25
26. Schedule Development
Techniques - Critical Path Method
• Forward pass - The first step in determining your critical path is to
complete a forward pass through the network diagram. This means that
you are working from the left to the right of your network diagram to
calculate early start (ES) and early finish (EF)
• Backward pass - The next step to complete the critical path is to
complete a backward pass . This means you start at the finish of your
network diagram and work back though each path until you reach the
start. This gives you two calculations, late finish (LF) and late start (LS)
May 2011
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27. Schedule Development
Techniques - Critical Path Method
Network diagram with task duration
Task ES EF LS LF Float
A 0 3 0 3 0
B 3 5 3 5 0
C 3 13 7 17 4
D 5 20 5 20 0
E 13 16 17 20 4
May 2011
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28. Schedule Development
Techniques - Duration Compression : Crashing
• Crashing is a technique that looks at cost and schedule trade-offs.
• Crashing is typically implemented by adding more resources to the
critical path tasks in order to complete the project more quickly.
• Crashing could also be accomplished by requiring mandatory
overtime for critical path tasks, by speeding up delivery times from
vendors, and so on.
• Crashing can produce the desired results if used wisely, but you
should be aware that crashing the schedule may increase risks and/or
impact your budget.
May 2011
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29. Schedule Development
Techniques - Duration Compression : Fast tracking
• Fast tracking is performing two tasks in parallel that were previously
scheduled to start sequentially.
• There is a great deal of risk in fast tracking because there could be
reasons why one task must be completed before another.
• It often results in rework, increases risk & requires more attention to
communications.
May 2011
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30. Schedule Development
Project Schedule
The project schedule includes at least a planned start date and planned
finish date for each schedule activity. Common methods are:
• Project schedule network diagrams. These diagrams, with activity
date information, usually show both the project network logic and the
project’s critical path schedule activities.
• Bar charts. These charts, with bars representing activities, show
activity start and end dates, as well as expected durations. Bar charts
are relatively easy to read, and are frequently used in management
presentations.
• Milestone charts. These charts are similar to bar charts, but only
identify the scheduled start or completion of major deliverables and key
external interfaces.
May 2011
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32. Schedule Development
Project Schedule
Gantt charts are probably one of the most commonly used methods to
display the project schedule. They can show milestones, deliverables,
subdeliverables, or all the activities of the project, if needed. Gantt
charts typically display the tasks using a horizontal bar chart format
across a timeline. Gantt charts are easy to read and can show the activity
sequences, start and end dates, resource assignment, dependencies, and
critical path.
May 2011
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35. Schedule Control
Definition
• Schedule control is concerned with:
- Determining the current status of the project schedule
- Influencing the factors that create schedule changes
- Determining that the project schedule has changed
- Managing the actual changes as they occur
• Schedule control is a portion of the Integrated Change Control process
May 2011
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38. Pop Quiz
Question 1
Which of the following is not true for the critical path?
A. It has zero float.
B. It ’ s the shortest activity sequence in the network.
C. You can determine which tasks can start late without impacting the
project end date.
D. It controls the project finish date.
May 2011
Slide 38
39. Pop Quiz
Question 2
You are a project manager for a major movie studio. You
need to schedule a shoot in Kashmir during ski season. This
is an example of which of the following?
A. External dependency
B. Finish - to - start relationship
C. Mandatory dependency
D. Discretionary dependency
May 2011
Slide 39
40. Pop Quiz
Question 3
What is analogous estimating also referred to as?
A. Bottom - up estimating
B. Expert judgment
C. Parametric estimating
D. Top - down estimating
May 2011
Slide 40
41. Pop Quiz
Question 4
You are working on your network diagram. Activity A is a
predecessor to Activity B. Activity B cannot begin until
Activity A is completed. What is this telling you?
A. There is a mandatory dependency between Activity A and Activity B.
B. There is a finish - to - start dependency relationship between Activity
A and Activity B.
C. Activity A and Activity B are both on the critical path.
D. Activity B is a successor to multiple tasks.
May 2011
Slide 41
42. Pop Quiz
Question 5
What is the most commonly used form of network
diagramming?
A. ADM
B. Precedence diagramming
C. CPM
D. PERT
May 2011
Slide 42
43. Pop Quiz
Question 6
What are the crashing and fast track techniques used for?
A. Duration compression
B. Activity sequencing
C. Precedence diagramming
D. Activity Definition
May 2011
Slide 43
44. Pop Quiz
Question 7
Which of the following is true for float or slack time?
A. It ’ s calculated by adding the durations of all activities and dividing
by the number of activities.
B. It ’ s time that you add to the project schedule to provide a buffer or
contingency.
C. It’s the amount of time an activity can be delayed without delaying
the project completion.
D. It is only calculated on the longest path of the network diagram.
May 2011
Slide 44
45. Pop Quiz
Question 8
Which of the following is not a tool used to determine a
project ’s critical path?
A. Forward pass
B. Mandatory dependency
C. Float calculation
D. Backward pass
May 2011
Slide 45
46. Pop Quiz
Question 9
Activity B on your network diagram has a most likely estimate
of 8 days, a pessimistic estimate of 11 days, and an optimistic
estimate of 6 days. What is the three – point PERT estimate
for this task rounded to the nearest whole number?
A. 11 days
B. 25 days
C. 8 days
D. 6 days
May 2011
Slide 46
47. Pop Quiz
Question 10
Which of the following is not true for critical path activities?
A. The early start is always less than the late start.
B. These activities are on the longest path on the network diagram.
C. The float is zero.
D. The late finish is always the same as the early finish.
May 2011
Slide 47
48. Pop Quiz
Question 11
You are working on a project in which the time to complete
the project has been heavily restricted and funds are short.
You have one resource working on preparing six servers for
use in a balanced web array. The servers will all look basically
alike. What technique can you use to slim down some of the
time required to perform this task in the project?
A. Fast tracking
B. Crashing
C. Reducing the number of servers
D. Purchasing a server that runs a number of virtual machines
simultaneously
May 2011
Slide 48
49. Pop Quiz
Question 12
Your task requires 4 miles of paving, and it will take 30 hours
to complete a mile. On a past project similar to this one, it
took 150 hours to complete. Which of the following is true
regarding this estimate?
A. The total estimate for this task is 120 hours, which was derived using
expert judgment.
B. The total estimate for this task is 120 hours, which was derived using
parametric estimating.
C. The total estimate for this task is 150 hours, which was derived using
analogous estimating.
D. The total estimate for this task is 150 hours, which was derived using
expert judgment.
May 2011
Slide 49
50. Pop Quiz
Question 13
You are in the process of developing a project schedule for a
new project for which you have just completed the WBS.
What would be the smart next step in figuring out what tasks
go into the project schedule?
A. Develop an activity list.
B. Determine the critical path tasks.
C. Develop a network diagram.
D. Estimate activity duration.
May 2011
Slide 50
51. Pop Quiz
Question 14
You have defined a task in a project schedule in which your
team members will develop an XML application that uses a
MySQL back end. Although the data base administrator
(DBA) has plenty of experience with Oracle and Microsoft
SQL Server, he has never been exposed to MySQL. Which of
the following elements will most likely be affected?
A. Resource allocation
B. Task estimation
C. Activity definitions
D. Determining critical path tasks
May 2011
Slide 51
52. Pop Quiz
Question 15
How long is the critical path in days in the graphic shown
here?
A. 13 days
B. 20 days
C. 27 days
D. 30 days
May 2011
Slide 52
53. Pop Quiz
Question 16
Which path represents the critical path?
A. A-E-F-G
B. A-C-D-G
C. A-B-D-G
D. A-B-D-F-G
May 2011
Slide 53
