Hi Dinesh,

I think this should be useful. I got it from Primavera Help.

How P3 summarizes data

This topic describes how P3 displays summary information for the following data items:

Calendar ID: When you summarize and show the calendar ID, if all the activities in the summary group are not assigned to the same calendar, P3 uses the summary calendar specified in the Summary Calculations dialog box (choose Tools, Options, Summarization). If all activities in the summary group are assigned to the same calendar, P3 uses that calendar.

Costs and quantities: P3 totals cost and quantity data items, such as budgeted cost, budgeted quantity, cost at completion, scheduled budget, and units per timeperiod, by adding the values for each activity in the summary.

Custom data items: P3 summarizes custom data items according to type. For example, items representing start dates show the earliest date, and items for finish dates show the latest dates. A precision or numeric custom data item is totaled for the summarized activities. A character-based custom data item displays a blank if all activities are the same.

Dates: If you display early dates, P3 shows the earliest early (or actual) start and the latest early (or actual) finish dates. The same rules apply for late dates and target early and late dates.

Durations: P3 summarizes original and remaining duration values. For activities with no progress, the original and remaining durations are the number of workperiods between the earliest early start and latest early finish dates. If the summary activity has an actual start date, P3 calculates the original duration from the actual start date to the latest early finish date. P3 calculates remaining duration from the "internal" early start date to the latest early finish date, in this case. P3 keeps track of the early start date for each activity even when you assign an actual start date; this is referred to as the "internal" early start date of the remaining duration.

If the summary activity is 100 percent complete, P3 calculates the original duration as the difference between the actual start and the actual finish dates; the remaining duration is zero. P3 considers nonworktime when summarizing activity data, based on calendar assignments. For example, if all activities in the summary are assigned to the same calendar, P3 uses that calendar. If activities are assigned to different calendars, P3 uses a continuous calendar, unless you enter a specific calendar in the Summary Calculations dialog box (Choose Tools, Options, Summarization).

If you display actual duration, P3 calculates the data value as follows:

• Earliest Actual Start - Data Date (for activities with no actual finish date)
• Earliest Actual Start - Latest Actual Finish (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. Use the Schedule/Level Calculation Options dialog box to set this option (click Options in the Schedule dialog box). If you base float on start dates, and all activities are assigned to the same calendar, total float is the difference between the earliest late start and the earliest early start dates in workperiods. For finish dates, P3 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. If all activities are not assigned to the same calendar, P3 defines total float based on the calendar specified in the
Summary Calculations dialog box (choose Tools, Options, Summarization).

Progress: When summarizing activities, you can base progress on activity durations, resource use, or costs to date. Use the Summary Calculations dialog box (choose Tools, Options, Summarization) to specify how to measure percent complete. The simplest measure uses duration to compare the amount of time remaining to complete the activities to their original duration. The following ratio is used for each summarized group:

[(Sum of the Original Duration - Sum of the Remaining
Duration) ¸ Sum of the Original Duration] x 100

Resource units and costs provide a more exact measure of actual use within each summarized group.

If your project is labor-intensive, you may want to use resource units. If your project includes both labor and materials, the cost method may be the best approach, since P3 does not distinguish between different units of measure for resources. The resource and cost methods calculate the percent complete for each summarized group as the following:

(Sum of Earned Value ¸ Sum of Budget) x 100

P3 calculates the earned value as the resource percent complete times the budget. If no resource percent complete is specified, P3 uses the schedule percent complete for the activity. The budget can be taken from either the current or the target schedule. Use the Earned Value Calculations dialog box to specify which budget to use to calculate earned value.
Resource percent complete is calculated according to the following equations:

• If Budgeted Cost = 0, then
  Resource percent complete = Sum of Earned Value Quantity (EVQ) ¸ Sum of Budget Quantity
• If Budgeted Cost ¹ 0, then
  Resource percent complete = Sum of Earned Value Cost (EVC) ¸ Sum of Budgeted Cost

where EVQ = Budgeted Quantity x Percent Complete and EVC = Budgeted Cost x Percent Complete

Note P3 calculates summary resource percent complete if at least one activity in the summary has a resource percent complete; otherwise, the resource percent complete is blank.

Special cases for activity data items: Some activity data items cannot be summarized. When showing the following data items, if one activity exists for the selection, the value for that activity appears; if more than one activity applies to the cell and the activities have different values, a blank cell appears:

Activity ID*, Activity description*, Activity type, Free float, WBS value, Character-based custom data items, Blank
column

*When showing subtotals or totals, P3 displays the word Subtotal or Total in the first column of the subtotal or grand total row when either Activity ID or Activity description is defined as the first Activity column.

For Activity codes and Activity ID codes, P3 displays a value if all values in the summary are the same.

Special cases for resource/cost data: Certain resource or cost data items cannot be summarized. If one activity with one resource exists for the selection, or all resources are the same, a value appears; if more than one value applies to the cell, a plus (+) appears along with the first value for the first activity in the group.

Cost account (11 characters), Cost account (12 characters), Resource

When summarizing the following items, a blank cell appears for the following items:
Cost account category, Resource curve, Resource duration, Resource lag

Target data, comparison data, and variances: Each target, comparison, or variance data item classifies as either a date or a duration data item. See Dates and Durations earlier in this topic for descriptions of how dates and durations are summarized.

Cheers,
Ali Vessali

[Note: I edited this post for formatting (hopefully it is easier to read) - Moderator]