The Critical Path Method (CPM) - Construction Project Scheduling and Control - page 84

(23, 31) and (32, 33), respectively. This makes A-C-G-I-K the critical path,
even though its “length” is only 23 days, without taking the constraint in
consideration.
• Scenario 3 : Assume the crew for activity I is unavailable until day 22 (a delay
of 3 days). This delays the completion of that activity until day 30 and the
completion of the project until day 32, making A-B-E-I-K the critical path.

From the preceding discussion, we conclude that the critical path in a network
is the longest continuous path from start to finish, taking into consideration all
time-consuming and time-impacting factors. This definition will take another twist
in Chapter 11 with the introduction of program evaluation and review technique
(PERT), which considers a range of durations of each activity. PERT considers not
only the length of the path but also the uncertainty (variance/standard deviation),
which measures the confidence in finishing the project by a certain date.

Tip Box 4.14

Make sure that you show “submittal review cycle,” taking into consideration the
possibility of rejection. Also show procurement activities.

CHAPTER 4 EXERCISES
1. For the following schedule, draw the node network, perform the CPM calcula-
tions, mark the critical path, and complete the table.

Activity Duration IPA ES EF LS LF TF FF

A 3 -

B 7 A

C 4 A

D 5 B

E 8 B, C

2. For the following schedule, draw the node network, perform the CPM calcula-
tions, mark the critical path, and complete the table.

Activity Duration IPA ES LS EF LF TF FF

A 7 -

B 10 -

C 15 A

D 8 A, B

E 4 C, D