The CPM Procedure |
SUCCESSOR variables / lag options ;
SUCC variables / lag options ;
The SUCCESSOR statement is required when data are input in an AON format. This statement specifies the variables that contain the names of the immediate successor nodes (activities) to the ACTIVITY node. These variables must be of the same type and length as those defined in the ACTIVITY statement.
If the project does not have any precedence relationships, it is not necessary to use the SUCCESSOR statement. Thus, you can specify only the ACTIVITY statement without an accompanying SUCCESSOR statement.
If the precedence constraints among the activities have some nonstandard relationships, you can specify these using the LAG options. The following is a list of LAG options.
In addition to the type of relation, you can also specify a lag duration and a lag calendar in the same variable. The relation_lag_calendar information is expected to be specified as
keyword _ duration _ calendar
where keyword is one of ' ', FS, SS, SF, or FF, duration is a number specifying the duration of the lag (in interval units), and calendar is either a calendar name or number identifying the calendar followed by the lag duration. A missing value for the keyword is assumed to mean the same as FS, which is the standard relation of finish-to-start. The other three values, SS, SF, and FF, denote relations of the type start-to-start, start-to-finish, and finish-to-finish, respectively. If there are no LAG variables, all relationships are assumed to be of the type finish-to-start with no lag duration. Table 2.19 contains some examples of lag specifications.
Table 2.19: Lag SpecificationsActivity | Successor | LAG | Interpretation |
---|---|---|---|
A | B | SS_3 | Start to start lag of 3 units |
A | B | _5.5 | Finish to start lag of 5.5 units |
A | B | FF_4 | Finish to finish lag of 4 units |
A | B | _SS | Invalid and ignored (with warning) |
A | SS_3 | Ignored | |
A | B | SS_3_1 | Start to start lag of 3 units w.r.t. calendar 1 |
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