How does Primavera P6 summarize data in the Summary / Grouping Band

We may wonder How does P6 calculates and displays summary information for costs, quantities, user defined fields, dates, durations, float, progress…

I will explain it in this article.

These calculations and display summaries are based on the currently visible activities. Activities removed from the layout by filters are not included in the calculations and summaries.

Costs and quantities:

P6 totals cost and quantity data items, such as budgeted cost and budgeted quantity, by adding the values for each activity in the summary.

Dates: 

If you display early dates, P6 shows the earliest early (or actual) start and the latest early (or actual) finish dates. The same rules apply for late dates and baseline early and late dates.

User Defined Fields: 

P6 summarizes user fields according to type. For example, items representing start dates show the earliest start date, and items for finish dates show the latest finish dates. A numeric user field is totaled for the summarized activities. A text-based custom user field never summarized.

Durations: 

P6 summarizes original and remaining duration values. For activities with no progress, the original and remaining durations are the number of work periods between the earliest start and latest finish dates and the earliest remaining start and latest remaining finish dates respectively. If the summary activity has an actual start date, P6 calculates the original duration from the actual start date to the latest finish date. In this case, P6 calculates remaining duration from the earliest remaining early start date to the latest remaining early finish date.

If the summary activity is 100 percent complete, P6 calculates the original duration as the difference between the actual start and the actual finish dates; the remaining duration is zero.

For version 7.0 and later:

• In a single project, if all activities under a particular grouping are using the same calendar, the summary band will calculate duration based on that calendar.
• In a single project, if activities under a particular grouping are using a different calendar, the summary band will calculate duration based on the Project Default Calendar, set under Enterprise, Projects, Defaults tab.
• In multiple projects, if activities under a particular grouping are using different calendars, and the projects have a different Project Default Calendar, the summary band will calculate duration based on the Global Default Calendar (same as 6.2.1 and earlier).

For versions 6.2.1 and earlier:

• Summary duration is calculated as the time between the earliest Start date of the included activities to the latest Finish date of the included activities according to the Global default calendar.  When multiple activities are included in a band, the summary duration is rarely equal to the longest activity duration unless all the activities occur simultaneously and the activity calendar assignments are all set to the Global default calendar.

If you display actual duration, the data is calculated as follows:

• Data Date – Earliest Actual Start (for activities with no actual finish date)
• Latest Actual Finish – Earliest Actual Start (all activities in the summary must have an actual finish date)

Float: 

You can base total float of the summarized data on the start dates, finish dates, or most critical dates. Set this option in the Compute Total Float As field on the Advanced Scheduling Options dialog box.  If you base float on start dates, total float is the difference between the earliest late start and the earliest early start dates.  For finish dates, P6 uses the latest late finish and the latest early finish dates to calculate total float. The most critical float is the lowest total float encountered in the detailed activities from each summary group.

P6 defines total float based on the default global calendar in P6 6.2.1 and earlier versions.

Progress (% Complete):

Duration % Complete = x 100

Activity Percent (%) Completes: These do not roll up to summary level bands

For more detail kindly refer to following file:

Download : Primavera P6 Column_Summaries