2. 2
Project Planning and Control
Definition of Project Management
Work Breakdown Structure
Critical Path Scheduling
Ideal Completion Time
• Time vs. Cost tradeoffs
3. 3
Project Management
Project
• series of related jobs usually directed toward
some major output and requiring a significant
period of time to perform.
Project Management
• planning, directing, and controlling resources
(people, equipment, material) to meet the
technical, cost, and time constraints of the
project.
• Project or Program?
7. 7
Work Breakdown Structure
Allow the elements to be worked on
independently
Make them manageable in size
Give authority to carry out the program
Monitor and measure the program
Provide the required resources
8. 8
Project Control: Gantt
Chart
New I-5 Bridge Design
Month Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan
Pilot Study development
Pilot Study distribution
Pilot Study analysis
Time & Process analysis
Preliminary Report
Survey design & pretest
Survey translation & copy
Survey distribution
Market Model Report
Collect cost & price data
Simulation development
Simulation analysis
Final Report
9. 9
Critical Path Scheduling
A project must have:
• well-defined jobs or
tasks whose
completion marks the
end of the project;
• independent jobs or
tasks;
• and tasks that follow a
given sequence.
10. 10
CPM with Single Time Estimate
Consider the following HR consulting project:
Develop a critical path diagram and determine the
duration of the critical path and slack times for all
activities
Activity Designation Immed.Pred. Time(Weeks)
Assess customer's needs A None 2
Write and submit proposal B A 1
Obtain approval C B 1
Develop service vision and goals D C 2
Train employees E C 5
Quality improvement pilot groups F D, E 5
Write assessment report G F 1
12. 12
Moving forward on the diagram (left to right):
Determine early start and early finish times
ES=0
EF=2
ES=2
EF=3
ES=3
EF=4
ES=4
EF=9
ES=4
EF=6
?
A, 2 B, 1 C, 1
D, 2
E, 5
F, 5 G, 1
13. 13
When F can start depends on when
predecessors (D & E) finish
ES=9
EF=14
ES=14
EF=15
ES=0
EF=2
ES=2
EF=3
ES=3
EF=4
ES=4
EF=9
ES=4
EF=6
A, 2 B, 1 C, 1
D, 2
E, 5
F, 5 G, 1
14. 14
Moving backwards on the diagram (right to left):
Determine late starts and late finish times
ES=9
EF=14
ES=14
EF=15
ES=0
EF=2
ES=2
EF=3
ES=3
EF=4
ES=4
EF=9
ES=4
EF=6
A, 2 B, 1 C, 1
D, 2
E, 5
F, 5 G, 1
LS=14
LF=15
LS=9
LF=14
LS=4
LF=9
LS=7
LF=9
?
16. 16
Critical Path & Slack
slack = amount of flexibility = LS-ES or LF-EF
Critical path= completion time of the project (project bottleneck). Connect all
points on path which have no slack
ES=9
EF=14
ES=14
EF=15
ES=0
EF=2
ES=2
EF=3
ES=3
EF=4
ES=4
EF=9
ES=4
EF=6
A, 2 B, 1 C, 1
D, 2
E, 5
F, 5 G, 1
LS=14
LF=15
LS=9
LF=14
LS=4
LF=9
LS=7
LF=9
LS=3
LF=4
LS=2
LF=3
LS=0
LF=2
Duration = 15 weeks
Slack=(7-4)=(9-6)= 3 Wks
17. 17
Time-Cost Models
Basic Assumption: Relationship
between activity completion time and
project cost
Time Cost Models: Determine the
optimum point in time-cost tradeoffs
• Activity direct costs
• Project indirect costs
• Activity completion times
18. 18
Time-cost Trade-off
“Crashing” a project
Prepare a CPM-type network diagram
Determine the cost per unit of time (usually
assume days) to expedite each activity.
NT=normal time CT= crash time
NC=normal cost CC=crash cost
cost to crash each day = (CC-NC)/(NT-CT)
Compute critical path
Shorten the critical path at the least cost
Determine the minimum cost schedule.
19. 19
A, 2
B, 5
C, 4
D, 3
Activity Cost per day to Expedite Number of possible Days activity may be shortened
A $ 4 1
B $ 3 3
C $ 2 1
D $ 2 2
20. 20
Crashing
Current
Critical Path
Remaining
days activity
may be
shortened
Cost per Day
to Expedite
each Activity
Least cost
activity to
expedite
Total Cost of
all Activities
in network
Project
Completion
time
ABD All $26 10
ABD A-1, B-3,
D-2
A-4, B-3,
D-2
D $28 9
ABD A-1, B-3,
D-1
A-4, B-3,
D-2
D $30 8
ABD A-1, B-3 A-4, B-3 B $33 7
ABCD A-1, B-2,
C-1
A-4, B-3,
C-2
A $37 6
ABCD B-2, C-1 B-3, C-2 B & C $42 5
ABCD B-1 B-3 B $45 5
22. 22
Bike Path Project:
Activity Description Predecessor Estimated time
A Survey for paths None 2 weeks
B Re-route traffic None 1 weeks
C Move utilities None 4 weeks
D Prepare new path
bed
A,B,C 15 weeks
E Dig and prepare
drainage
D 5 weeks
F Set forms and
reinforcements
D 3 weeks
G Pour concrete E,F 2 weeks
H Build curbs G 3 weeks
I Pave surface G 2 weeks
23. 23
Cost Trade-offs
The contractor will get a $100,000 bonus for
completing the project within 25 weeks. Some of
the activities can be shortened, but will cost
more:
• Activity D: $10,000 per week for up to 3 weeks
• Activity E: $8,000 per week for up to 1 week
• Activity H: $6,000 per week for up to 1 week
• Activity I: $8,000 per week for up to 1 week
What should he/she do?