Schedule Updating and Project Control - Construction Project Scheduling and Control - page 170

Example 7.1
In example 4.3, 10 days after the project has started, you receive the following
report:
Activities A and D are complete, actual dates: A (0, 2), D (5, 9).
Activity B started on day 5. Remaining duration = 2days.
Activity C started on day 2. Some problems were encountered. Remaining
duration = 4days.
The duration for activity F was adjusted to 8 days.
Activity J has been canceled.
The duration for new activity P is 4 days. IPA = E and F. ISA (immediately
succeeding activity) = K.
Update the logic. Note : When we delete activity J, the schedule must verify
whether we should assign its predecessor to its successor. In other words,
would activity F become a predecessor to activity K?
Solution
Example discussion: Figure 7.8a shows the solution of Example 4.3.
Figures 7.8b and 7.8c show the update process according to the information
given in the exercise statement.
As we observe, the project in example 7.1 slipped by two days. This is
the first part of the information. The other part is why the schedule slipped.
There were several changes in the update, that is, departures from the original
schedule:
a. Activity C took 2 more days than originally planned.
b. Activity F's duration increased from 5 to 8.
c. Activity P was added.
d. Activity B had not been completed, even though its early finish date
was day 9.
e. Activity H had not started yet, even though its early start date was
day 6.
Which one of these factors caused the 2-day delay in the completion of
the schedule? Or, is it a combination of these factors?