This document contains instructions and questions for an exercise on project management concepts including critical path method (CPM) and program evaluation and review technique (PERT). It asks students to perform calculations for various networks and project schedules, including determining float, drawing time-scaled diagrams, and identifying critical activities. It also provides a multi-step case study of a gas station construction project and asks students to model it using CPM.

1. Mansoura University Construction Project Management
Faculty of Engineering 3rd Year Civil
Structural Eng. Dept. 2006-2007
Exercise 4
Due date: Wednesday, Nov 2nd 2005
1. The free float is defined as:
a. The amount of time an activity can be delayed without affecting the following activity.
b. The amount of time an activity can be delayed without affecting total project duration.
2. Total float equals:
a. Late finish minus early finish c. Late start minus early start
b. Late finish minus (early start + duration) d. All of the above
3. State True (T) or False (F):
a. The critical activities can be determined easily when using the bar chart.
b. The network must have definite points of beginning and end.
c. The network must be continuous from start to end.
d. There’s no dummy activities in the arrow networks,
e. A forward pass is used to determine late start and late finish times.
f. The time for completing a project is equal to the sum of the individual activity times.
4. For the Following project data, answer the following questions:
Activity Duration (days) Predecessor
A 2 --
B 6 A
C 3 A
D 1 B
E 6 B
F 3 C, D
G 2 E, F
a) Draw an AOA network and perform forward and backward pass calculations?
b) Draw an AON network and perform forward and backward pass calculations?
c) Draw a time-scaled diagram of the project?
d) Tabulate activities ES, EF, LS, LF, TF, and FF.
e) What is the effect of delaying activity D by 3 days?
5. For the following AOA network, determine the following:
a. Calculate ES, LF, & TF for all activities. Identify critical ones.
b. Draw an early Bar Chart for the project.
c. What is the effect of delaying activity “H” by two days on the total project duration?
Construction Management 1 Dr. Emad Elbeltagi

2. Mansoura University Construction Project Management
Faculty of Engineering 3rd Year Civil
Structural Eng. Dept. 2006-2007
3 D (8) 9
A (4) H (4)
1 B (6) E (10) 11 I (8) 15 K (5) 17
5
C (2) F (16)
J (10)
7 G (6) 13
6. Perform PDM calculations for the project below and determine activity times. Durations are
shown on the activities
I
(2)
B D G
(4) (1) (1)
A J L
(1) (7) (2)
C E H
(1) (2) (1)
F K
(2) (4)
7. A gas station is proposed to be built on an already developed site. It will consist essentially of
a sales outlet and an office block. The sales outlet comprises of cash office and gas pumps. The
manager’s office building, which also houses public washrooms and an air compressor, is called
the office block. Adjacent to pumps will be a concrete pit that will house the gas tanks.
The entire area, excluding the office and pumps site, is covered with a concrete slab, and there is
a low perimeter wall in the rear. The utility company has undertaken to install an electric meter
on the site and connect it to the mains. Gasoline pumps must be obtained from the
manufacturers, and after being installed, they are to be connected to the gasoline tanks and the
power supply. Before use the local authority to ensure safety and compliance with regulations
must inspect them. Gasoline tanks are housed in concrete pits and covered by concrete slabs.
Before they are covered, however, the tanks and the associated pipe work have to be inspected
by the local authority. The sales outlet base is excavated first, the pipe work and tanks second,
the office block third, and the trench for underground services last. After the excavation for the
tanks and pipe work is completed, work can proceed on the construction of the perimeter wall
and air points.
Compressed air for inflated tires will be supplied by an electrically driven compressor, which
must be inspected by a competent person before the compressor is put into use. The air lines to
Construction Management 2 Dr. Emad Elbeltagi

3. Mansoura University Construction Project Management
Faculty of Engineering 3rd Year Civil
Structural Eng. Dept. 2006-2007
the “free air” points are installed with the general underground services, and the points
themselves are mounted on the perimeter wall. The air pints can be hooked up after the concrete
slab has been poured. Mobilization to start work comprises, among other preparations, the
moving of a trailer to the site to store tools, furnishings, and any weather prone parts and to serve
as the site office. Similarly, when work at the site is completed, the trailer will be removed, and
all scaffolding and construction equipment taken away. This is known as “demobilization and
clean up of site.”
You are required to determine the project duration, critical path(s), and tabulate activity times
(ES, EF, LS, LF, TF, and FF).
No Activity Description Duration
A Excavate for sales outlet 1
B Construct sales outlet base 1
C Construct cash office 2
D Obtain pumps 16
E Install pumps 2
F Connect pumps 1
G Inspector approves pumps installation 2
H Paint & furnish office & washrooms 2
I Connect office & toilet lighting 1
J Excavate for office block 1
K Construct office block 1
L Build office & washrooms + services 15
M Install electric meter 14
N Connect main cable to meter 1
O Install area lighting 4
P Mobilize site 1
Q Set out and level site 1
R Excavate & lay underground services 1
S Excavate for pipes and tanks 1
T Construct concrete pit 2
U Obtain pipes and tanks 2
V Install pipes and tanks 3
W Obtain compressor 10
X Install compressor 1
Y Connect power to compressor 1
Z Inspection of compressor 2
AA Backfill and cover tanks 1
BB Pour concrete slab 2
CC Construct perimeter wall + air points 2
DD Connect air points 1
EE Demobilize and clean site 1
FF Inspection of pipes and tanks 2
Construction Management 3 Dr. Emad Elbeltagi

4. Mansoura University Construction Project Management
Faculty of Engineering 3rd Year Civil
Structural Eng. Dept. 2006-2007
8. For the following list of activities, draw a time-scaled diagram and mark the critical path.
Determine activities ES, EF, LS, LF, FF, and TF.
Activity Duration (days) Predecessor
A 4 --
B 10 A
C 2 A
D 6 C
E 15 B, D
F 4 B, D
G 3 F
H 2 B, D
I 1 E, G, H
J 3 I
K 2 E
L 1 J
M 2 K, L
9. For the following PDM, perform the forward pass and backward pass calculations. Determine
the project duration and critical path. Tabulate the ES, EF, LS, LF, TF, and FF information for
each activity.
E
FF7
7
A SS3, FF4
B SS2
D F SS8
G
10 8 12 FF5 9 12
SS8
J
C 0
SF5
8
FS6
H FF3
I
10 8
Construction Management 4 Dr. Emad Elbeltagi