The Critical Path Method (CPM) - Construction Project Scheduling and Control - page 71

Figure 4.9 Node formats: (a) activity ID and name, duration, early start (ES), early finish
(EF), late start (LS), late finish (LF), total float (TF), and free float (FF); (b) activity ID and
name, ES, EF, LS, LF, TF, original duration (OD), remaining duration (RD), and percent
complete (PC). If early dates are followed by the letter A , they are actual dates, and late
dates are not used
It is not uncommon to include information such as activity codes (responsibility,
area, phase, etc.) or cost in the activity box. The challenge becomes balancing the
amount of information inside the box, the legibility and clarity of the information,
and the size of the chart.
Lags and Leads into CPM Networks
As defined in Chapter 3, a lag is a minimum mandatory waiting period between the
completion (or start) of an activity and the start (or completion) of its successor.
Figure 4.10 Lags in a CPM network