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Editing Stored Period Performance

2 replies [Last post]
Mon, 2009-05-25 00:11
Mark Porter
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Joined: 8 Aug 2007
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All,

I have some stored period values that I have had to edit (Don’t ask!!) on my schedule...

My question is... Do I also have to also manually edit the period earned value data (As I’m currently showing negitive values when I only adjust the actual units & cost) and if so, how to I calculate these values in the absence of a stored % complete

Kind Regards

Mark Porter
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Tue, 2009-06-09 09:30
#1
Jason LI
User offline. Last seen 3 years 42 weeks ago. Offline
Joined: 1 Jan 2008
Posts: 37
Groups: Petro-Chem / Oil & Gas
hi, mark
I have a question about your below description, please forther explain.
If the activity is started and the first period of January is stored with a cost of $2,000, and then the Baseline budget is changed to $12,000.
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Tue, 2009-06-02 23:08
#2
Mark Porter
User offline. Last seen 10 weeks 3 days ago. Offline
Joined: 8 Aug 2007
Posts: 55
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Hi All,

With some help from Primavera support and the knowledgebase I have found the following solution to my problem...

This may be of some interest to those of you who are storing period performance and get negative values

prim44205

The Planned Value (PV) or Earned Value (EV) financial period values are calculated as:

Actual This Period = Actual to Date - Stored (Past Period Actuals)

A negative variance can occur if the calculated Planned Value or Earned Value is less than the stored value.

When the results are greater or less than expected it can be an indication that the Baseline budget has been increased or decreased after some Financial Periods have already been stored

For Example:

A budget of $6,000 is applied to an activity in the Baseline of a project.

The activity spans from January through to March and it is assumed that there are an equal number of work days in each month,

The Planned Value calculation is computed as the BAC * Schedule % complete from the baseline.

Based on this information, the schedule % complete at the end of each month will equal the following:

Jan = 33.3%,
Feb = 66.6%,
March = 100%.

Therefore the planned distribution of the costs will equal:

Jan (33.3% * $6000) = $2,000
Feb (66.6% * $6000) - $2000 (Jan Planned) = $2,000
Mar. (100% * $6000) - $4000 (Jan & Feb Planned) = $2,000

If the activity is started and the first period of January is stored with a cost of $2,000, and then the Baseline budget is changed to $12,000.

Jan = $2,000 (As it is a stored financial period value)

The second period of February is then completed, whilst noting the following values will be stored;

February (66.6% * 12,000) = $8,000 - previously stored financial period data from January ($2000) =$6,000 (stored for February)
March planned value (100% * $12,000) =$12,000 - Jan ($2000) and Feb (6,000) = $4,000

As you can see the February values are re-calculated to account for the change to the budget, therefore the Planned Value is $8,000 (two months of $4,000) minus Past Period Actual
of $2,000, which equals $6,000.
March planned value would equal $4,000.

Even though you might expect that the planned value would spread among the three months as a lineal distribution of ($4,000 for January, $4,000 for February and $4,000 for March),
the program will not alter historical (stored) information when storing in future buckets, alternatively, like me you also may have thought that the planned work would be distributed as $2000 for January, $5000 for February and $5000 for March but this doesn’t account for the PV being calculated as BAC * Schedule % complete.

Earned Value:

Please note
The Earned Value is calculated as above whilst noting that the % complete is derived from the performance % complete.

Earned Value This Period = (BAC * Performance % Complete = EV to date) - sum of previous stored period EV.

Hope this info helps

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