Chapter 08 of ICT Project Management based on IOE Engineering syllabus. This chapter contains activity definition, decomposition of activities,activity attributes, schedule development and control etc....Provided by Project Management Sir of KU.

1. Project time management
Chapter 8

2. An old joke when it comes to project
time management
“The first 90 percent of a project
schedule takes 90 percent of the time.
The last 10 percent takes the other 90
percent of the time.”

3. Components of project time management

4. Creating activity list
• Creating the activity list relies on several
completed documents, knowledge, and actions.
Uses the following as inputs to the process:
• WBS
• Scope statement (description of the required work, and only
the required work, to complete the project)
• Historical information
• Constraints ( deadline, cost)
• Assumptions ( resources availability, weather condition)
• Expert judgment

5. Mapping the activities
• Once the activity list has been created, the
activities must be arranged in a logical sequence
• This process calls on the project manager and the
project team to identify the logical relationships
between activities
In practice:
“Sticky notes” can help sequence events. Put your
activities on sticky notes and then plot them out on a
white board. Draw arrows to show the relationship
between activities. Want to make a change? It’s easy to
rearrange the notes and the relationships

6. Scheduling
• Schedule is the conversion of a project action
plan into an operating timetable
• Basis for monitoring a project
• One of the major project management tools
• Work changes daily, so a detailed plan is
essential
• Not all project activities need to be scheduled at
the same level of detail

7. Scheduling
• Most of the scheduling is at the WBS level,
not the work package level
• Only the most critical work packages may be
shown on the schedule
• Most of the scheduling is based on network
drawings

8. The project network
A flow chart that graphically depicts the sequence,
interdependencies, and start and finish times of
the project job plan of activities
• Provides the basis for scheduling labor and equipment
• Enhances communication among project participants
• Provides an estimate of the project’s duration
• Provides a basis for budgeting cash flow
• Highlights “critical” activities and that can not be delayed
• Help managers get and stay on plan

9. Network scheduling advantage
• Consistent framework
• Shows interdependences
• Shows when resources are needed
• Ensures proper communication
• Determines expected completion date
• Identifies critical activities

10. Network scheduling advantage
• Shows which of the activities can be delayed
• Determines start dates
• Shows which task must be coordinated
• Shows which task can be run parallel
• Relieves some conflict
• Allows probabilistic estimates

11. Network scheduling techniques:
PERT and CPM
• The program evaluation and review technique
(PERT), was developed for the Polaris
missile/submarine project in 1958
• Critical path method (CPM), developed by DuPont
during the same time

12. Terminology
• Activity: an element of the project
that requires time
• Merge activity: an activity that has
two or more preceding activities on
which it depends
• Parallel activities: activities that can
occur independently and, if desired,
not at the same time
• Sequential activities: one activity must
be completed before the next one can
begin
A
C
DB

13. Terminology
• Immediate predecessor: an activity that must be
completed just before a particular activity can begin
• Event: the result of completing one or more activities
• Network: the combination of all activities and events
that define a project
• drawn left-to-right
• connections represent predecessors
• Path: a series of connected activities
• Critical: an activity, event, or path which, if delayed,
will delay the completion of the project

14. Terminology
• Critical path: the path through the project where, if
any activity is delayed, the project is delayed
• There is always a critical path
• There can be more than one critical path
• Burst activity: an activity that has more than one
activity immediately following it (more than one
dependency arrow flowing from it)
B
D
A C

15. Terminology
• Activity on Arrow - Arrows represent
activities while nodes stand for events
• Activity on Node - Nodes stand for
events and arrows show precedence

16. AON and AOA Format
Activity network, AON
format
Activity network, AOA
format

17. Constructing the network
• Begin with START activity
• Add activities without precedences as
nodes
• There will always be one
• May be more
• Add activities that have those activities
as precedences
• Continue

18. Constructing the critical path
• Forward pass – an additive move
through the network from start to finish
• Backward pass – a subtractive move
through the network from finish to start
• Critical path – the longest path from end
to end which determines the shortest
project length

19. Rules for forward/backward pass
Forward Pass Rules (ES & EF)
• ES + Duration = EF
• EF of predecessor = ES of successor
• Largest preceding EF at a merge point
becomes ES for successor
Backward Pass Rules (LS & LF)
• LF – Duration = LS
• LS of successor = LF of predecessor
• Smallest succeeding LS at a burst point
becomes LF for predecessor

20. Node labels
Early start ID number Early finish
Activity float Activity descriptor
Late start
Activity
duration
Late finish

21. Duration estimation methods
• Past experience
• Expert opinion
• Mathematical derivation – Beta distribution
• Most likely (m)
• Most pessimistic (b)
• Most optimistic (a)
TE: Estimated time for activity
σ: variance for activity duration

22. Solving the network

23. AON network

24. Calculating activity times
( )
( )
2
2
2
6
6
4
σσ
σ
=





 −
=
++
=
ab
bma
TE

25. The results

26. Critical path and time
AON network, showing activation duration and variance

27. Critical path and time

28. Critical path and time
AON network, showing earliest and latest start and finish
times, and critical path
The longest of the paths through the network is a-d-j using
43 days, which means that 43 days is the shortest time in
which the entire network can be completed. This is called
the critical time of the network, and a-d-j is the critical path,
usually shown as a heavy line

29. Slack
• Free slack (or Float)
• Is the amount of time an activity can be delayed after
the start of a longer parallel activity or activities
• Is how long an activity can exceed its early finish date
without affecting early start dates of any successor(s)
• Allows flexibility in scheduling scarce resources
• Sensitivity
• The likelihood the original critical path(s) will change
once the project is initiated

30. Slack

31. Slack
The project has a critical time of 43
days. Activity i must be finished by
day 43. Also activity i requires 18
days to be accomplished. i must be
started not later than day 25 ( 43-
18 = 25) if the project is to be
complete on day 43. Because i
cannot begin until activities g and h
have finished, the latest time (LF)
for each of these is also day 25.

32. Slack
The difference between the LS and the ES for an activity is
called its float or slack. In the case of activity i, it must be
started no later than day 25, but could be started as early as
day 24, so it has one day of slack. It should be immediately
obvious that all activities on the critical path have zero slack.
Zero slack activities cannot be delayed without making the

33. Slack
Another example,
consider activity f. Its
ES is day 20, which is
equal to the EF of its
predecessor activity b.
The LS for activity f is
43 -14=29.
If f is started later than
day 29, it will delay the
entire project.
Activity f has slack of
LS – ES = 29 – 20 = 9
days
To find the slack for any activity, we
make a backward pass (right to left)
through the network just as we made a
forward pass (left to right) to find the
critical path and time

34. Slack values

35. Precedence diagramming
• Finish to start
• Start to start
• Finish to finish
• Start to finish

36. Precedence diagramming
• Finish to start
• Start to start
• Finish to finish
• Start to finishFinish-to-start (FS): Task A must complete before Task B can
begin. Example: The foundation must be set before the framing
can begin.
Start-to-start (SS): Task A must start before Task B can start.
Example: A crew of painters is painting a house. Task A is to
scrape the flecking paint off the house and Task B is to prime the
house. The workers scraping the house must start before the other
workers can begin priming the house. All of the scraping doesn’t
Finish-to-finish (FF) : Task A must complete before Task B does.
Ideally, two tasks must finish at exactly the same time.
Start-to-finish (SF): It requires that Task A start so that Task B may
finish. Maybe encountered in construction and manufacturing.

37. Chances of meeting the deadline

38. Assignment:
• Consider the following project ( time given in days)
Calculate:
1. The network.
2. All expected activity
times, variances, and
slacks.
3. The critical path and
expected completion time.
4. The probability the
project will be done in 23
days.

40. More on Project Time
Management

41. How Do We Manage Time?
• Six processes
– Define Activities
– Sequence Activities
– Estimate Activity Resources
– Estimate Activity Durations
– Develop Schedule
– Control Schedule
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

42. Define Activities
Enterprise
Environmental
Factors
Organizational
Process Assets
Project Scope
Statement
Decomposition
Templates
Rolling wave planning
Expert judgment
Planning component
Inputs
OutputsTools & Techniques
Work Breakdown
Structure
WBS Dictionary
Project
Management Plan
Activity List
Activity Attributes
Milestone List
Requested Changes
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

43. Define Activities
• Rolling Wave Planning – Progressive planning
where near term work is broken down in detail
and distant work is kept at a higher WBS level
• Planning Component – WBS items that cannot be
broken down into work packages are put in a:
– Control Account – High level planning dates for
the scope to be defined
– Planning Package – Package includes scope to
be completed but no activities.

44. Sequence Activities
Project Scope
Statement
Activity List
Activity
Attributes
Precedence diagramming
method (PDM)
Arrow diagramming method
(ADM)
Schedule network templates
Dependency determination
Applying leads and lags
Inputs
OutputsTools & Techniques
Milestone List
Approved Change
Requests
Project Schedule
Network Diagrams
Activity List Updates
Activity Attributes
Updates
Requested Changes
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

45. Precedence Diagramming Method (PDM)
• Commonly called Activity on Node (AON), most
commonly used sequencing method
• Boxes are used to represent tasks with arrows
used for dependencies

46. Estimate Activity Resources
Enterprise
Environmental
Factors
Organizational
Process Assets
Activity List
Expert judgment
Alternatives analysis
Published estimating data
Project management
software
Bottom-up estimating
Inputs
OutputsTools & Techniques
Activity Attributes
Resource
Availability
Activity Resource
Requirements
Activity Attributes
Updates
Resource
Breakdown
Structure
Resource Calendar
UpdatesProject
Management Plan
Requested Changes
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

47. Estimate Activity Durations
Enterprise
Environmental Factors
Organizational Process
Assets
Project Scope
Statement
Expert judgment
Analogous estimating
Parametric estimating
Three-point estimates
Reserve Analysis
Inputs
Outputs
Tools & Techniques
Activity List
Activity Resource
Requirements
Activity Duration
Estimates
Activity attributes
updates
Resource Calendar
Activity Attributes
Project Management
Plan
•Risk Register
•Activity Cost
Estimates
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

48. Estimating Methods
• CPM (Critical Path Method)
– One time estimate per task
– Controls cost with flexible schedule
– Only on AOA networks (can have dummies)
• PERT (Program Evaluation and Review Technique)
– Three estimates per activity (Optimistic, Pessimistic, most likely)
– Emphasis on meeting schedule with flexible cost
– Only on AOA networks (can have dummies)

49. Estimating with PERT
• PERT Formula (Expected Duration)
– =(P+4M+O)/6
• Standard Deviation = (P-O)/6
• Variance = [(P-O)/6]2
Task O
Optimistic
M
Most Likely
P
Pessimistic
PERT
(Expected
Duration)
Std Dev Variance
A 2
days
4
days
8
days
4.3
days
1
day
1
day

50. Develop Schedule
Enterprise
Environmental Factors
Organizational Process
Assets
Project Scope
Statement
Schedule network analysis
Critical path method
Schedule compression
What-if analysis
Resource leveling
Critical chain method
Project management
software
Applying calendars
Adjustable leads and lags
Schedule model
Inputs
Outputs
Tools & Techniques
Activity List
Activity Resource
Requirements
Schedule baseline
Activity attributes
updates
Resource Calendar
Activity Attributes
Project Management
Plan
•Risk Register
•Activity Cost
Estimates
Project schedule
Schedule model data
Resource
requirements updates
Requested changes
Project management
plan updates
•Schedule
management
plan updates
Project calendar
updates
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

51. Scheduling from Estimates
• Critical Path
– Longest time through the network diagram, the
shortest time the project is expected to take
• Slack (or Float)
– The amount of time a task can be delayed without
impacting the project
– Calculated using:
• Late Start – Early Start (LS-ES)
Or
• Late Finish – Early Finish (LF-EF)
– Early Starts computed by making a “forward pass”
through the network while late starts are computed
using a “backward pass”

52. Critical Path Determination
• EF=ES+DUR-1
• LS=LF-DUR+1
• Slack=LF-EF or LS-ES
Task Name
ES
LS
EF
LF
DUR
Slack
4
2 2
23
1 9
863
2 10
8
9 0 10
4
3 0
7 8
1 0 2
Task A
Task B
Task C
Task D

53. Control Schedule
Schedule Management
Plan
Schedule Baseline
Schedule network analysis
Critical path method
Schedule compression
What-if analysis
Resource leveling
Critical chain method
Project management
software
Applying calendars
Adjustable leads and lags
Schedule model
Inputs
Outputs
Tools & Techniques
Performance reports
Schedule baseline
updates
Requested changes
Approved Change
Requests
Schedule model data
updates
Performance
measurements
Organizational
process assets
updates
Activity list updates
Recommended
corrective actions
Activity attribute
updates
Project Management
Plan updates
Define
Activities
Sequence
Activities
Estimate
Activity
Resources
Estimate
Activity
Durations
Develop
Schedule
Control
Schedule

54. Other Important Terms
• Lag – Inserted waiting time between tasks
• Free Slack – Available delay time without impacting start
of successor
• Total Slack – Amount of time a task can be delayed
without delaying project completion date
• Project Slack – Amount of time a project can be delayed
without impacting completion dates imposed by client
• Crashing – Adding resources to critical path items to
shorten schedule
• Fast Tracking – Performing critical path tasks in parallel
rather than series
• Resource Leveling – Adjusting completion dates of tasks
to meet available resources
• Heuristics – Rules of thumb