Schedule Updating and Project Control - Construction Project Scheduling and Control - page 162

Future
Current
Past
Current Data
Date
Previous Data
Date
Figure 7.1 Data date and update zones: past, current, and future
2. User's changes: User's changes are those that are made directly and deliber-
ately by the scheduler. They may not have anything to do with past events.
Let's imagine in the example shown in Figure 7.2a that everything is going
as planned; however, the contractor (or owner) decides to delay the start of
one activity (Painting) for 2 days, using a constraint (see Figure 7.2c). This is
a user-induced change that was not caused by predecessors, but it may have an
impact on its successors.
Tip Box 7.3
Updating information includes the actual performance, whether it matches or is dif-
ferent from the baseline, as well as changes in future activities and other schedule
information.
Frequency of Updating
Construction schedules may be updated monthly, biweekly, weekly, or according to
another time interval. Weekly and biweekly schedule updates are probably the most
common. Project managers must achieve a delicate balance between a period between