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Top Down Estimation

3 replies [Last post]
Fri, 2006-01-06 03:01
Amir Dadbakhsh
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Joined: 13 Oct 2004
Posts: 42
Groups: Petro-Chem / Oil & Gas
Dear fellows

I don’t know the usage of "Top Down Estimation…".
Can anybody give a practical example or even tell how use it in his/her job.

Thank you
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Replies

Wed, 2016-07-13 02:33
#1
Khuong Do
User offline. Last seen 2 years 2 weeks ago. Offline
Joined: 22 Feb 2010
Posts: 118
Groups: None

Hi,

I write an article regarding How does “Top Down Estimation” in Primavera P6 work?

If you're interested, kindly read it here https://doduykhuong.wordpress.com/2016/07/08/how-does-top-down-estimation-in-primavera-p6-work/

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Thu, 2006-01-12 04:56
#2
Charleston-Joseph...
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Hi Amir,

Maybe this kind of estimates is also related to TOP DOWN CONSTRUCTION.

Cheers,

Charlie
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Fri, 2006-01-06 07:29
#3
Mario Sanvitale
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Joined: 22 Sep 2005
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To use TDE effectively you should also be using Methodology Manager to define relative weights for elements of a project. TDE allocates units in accordance with the relative weighting of the WBS elements and activities therein. It’s like a "cascade" effect where at each level the balance is reallocated according to the relative weightings of each element at that level.

Example: If you have 100 units to allocate across two WBS elements and the relative weightings are 6 and 2, 75 units will go to the first, and 25 units to the second.

If the next level is activities, and there are three activities in WBS1, with relative weightings of 5, 6 and 7, the estimator will allocate the 75 units allocated to WBS1 as 21, 25 and 29 (rounded to whole values).

Similarly in WBS2 if there are two activities with relative weighting of 2 and 3, 10 units will go to activity 1 and 15 to activity 2.

The total units to be allocated can be entered by "Best Guess" based on historical evidence. If it’s an IT development you can use Function Points to estimate the total duration, but you will need to know the average function point delivery by resource.

Using Project Architect you can use metrics to develop first-pass estimates for total durations, assuming appropriate information available.

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