Understanding Lags and Leads in Primavera P6 8.2
A Lag is a duration that is applied to a dependency to make the successor start or finish earlier or later.
- A successor activity will start later when a positive Lag is assigned. Therefore, an activity requiring a 3-day delay between the finish of one activity and start of another will require a positive lag of 3 days.
- Conversely, a lag may be negative when a new activity may be started before the predecessor activity is finished. This is called a Lead or Negative Lag.
- Leads and Lags may be applied to any relationship type.
|An example of a FS with positive lag:|
|An example of a FS with negative lag:|
Here are some important points to understand about Lags in P6:
- The lag duration is calculated on the lag as in Microsoft Project and other Primavera products. A lag is not assigned to one or both of the Predecessor and Successor activities as in Asta Powerproject.
- Lags may be assigned one of four calendars from the Calendar for Scheduling Relationship lag drop down box in the General Schedule Options form. This form is opened by selecting Tools, Schedule… and clicking on the options tab.
The four Lag Calendar options are:
Ø Predecessor Activity Calendar,
Ø Successor Activity Calendar,
Ø 24-Hour Calendar, and
Ø Project Default Calendar.