Download Project Management 3e.

Change management control

Sources of Change
 Project
scope changes
 Implementation
 Improvement
ISE 491 - Ch. 6
of contingency plans
changes
1
Change management control

The change control process

Identify proposed changes.

List expected effects of proposed changes on schedule and
budget.

Review, evaluate, and approve or disapprove of changes
formally.

Negotiate and resolve conflicts of change, condition, and
cost.

Communicate changes to parties affected.

Assign responsibility for implementing change.

Adjust master schedule and budget.

Track all changes that are to be implemented.
ISE 491 - Ch. 6
2
The change control process
FIGURE 7.9
ISE 491 - Ch. 6
3
Benefits of a change control system
1.
2.
3.
4.
5.
6.
7.
8.
Inconsequential changes are discouraged by the formal
process.
Costs of changes are maintained in a log.
Integrity of the WBS and performance measures is
maintained.
Allocation and use of budget and management reserve
funds are tracked.
Responsibility for implementation is clarified.
Effect of changes is visible to all parties involved.
Implementation of change is monitored.
Scope changes will be quickly reflected in baseline and
performance measures.
ISE 491 - Ch. 6
4
Change
Request
Form (CR)
FIGURE 7.10
ISE 491 - Ch. 6
5
Change request log
FIGURE 7.11
ISE 491 - Ch. 6
6
PERT and PERT
Simulation
Chapter 7 Appendix
ISE 491 - Ch. 6
7
Program Evaluation Review Technique
(PERT)



Expands CPM methods to account for uncertainty
in activity times.
Assumes each activity duration has a range that
statistically follows a beta distribution.
PERT uses three time estimates for each activity:
optimistic, pessimistic, and a weighted average to
represent activity durations.
 Knowing
the weighted average and variances for each
activity allows the project planner to compute the
probability of meeting different project durations.
ISE 491 - Ch. 6
8
Activity and project frequency distributions
a. Activity times (beta)
b. Project time (normal)
from FIGURE A7.1
ISE 491 - Ch. 6
9
Activity time calculations

The weighted average activity time is computed
as follows:
(7.1)
ISE 491 - Ch. 6
10
Activity time calculations (cont’d)

The variability in the activity time estimates is
approximated by the following equations:
 The
standard deviation for each activity is,
(7.2)
 The
standard deviation for the entire project
(7.3)
Note the standard deviation of the activity is squared in this equation;
this is also called variance. This sum includes only activities on the
critical path(s) or path being reviewed.
ISE 491 - Ch. 6
11
An example: Activity times and variances
TABLE A7.1
ISE 491 - Ch. 6
12
Probability of completing the project

The probability of completing the project in the
time specified is determined by first computing a
z-score, as follows:
(7.4)

The probability, α, associated with the z-score is
the probability of completing the project on time.
ISE 491 - Ch. 6
13
Example: A hypothetical network
FIGURE A7.2
ISE 491 - Ch. 6
14
Possible project duration
TS = 67
TE = 64
ISE 491 - Ch. 6
from FIGURE A7.3
15
Probabilities associated with some Z
values
TABLE A7.2
ISE 491 - Ch. 6
16