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Top Down Estimation

4 replies [Last post]
Tue, 2007-01-16 10:31
Ijaz Ahmad
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Can any body explain a lit bit how Top down estimation works in P3eC? Also what is meant by Function Point?
Thanks
Ijaz
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Replies

Wed, 2016-07-13 02:35
#1
Khuong Do
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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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Wed, 2013-01-23 14:59
#2
Robert Gray
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Joined: 24 Jun 2009
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Groups: Petro-Chem / Oil & Gas

My Desktop at wotk has just been upgraded to Windows 7 (Previously Window XP).  I now find that when I try and run Tops down estimationg. P6 freezes and I have to force myself off.

The messeage that comes up when I do this is that P6 is waiting for a response from the user, but the expected Tops down estimation options window does not open.

I would appear that there is a compatability issue with window 7 and the Tops down estimationg function in p6.

Does anyone know how to resolve this

Regards

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Mon, 2007-01-22 00:29
#3
Alex Wong
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HI Gents

If you talk about top down estimation in Cost, then you need to start with your CBS- Cost Break Down Structure. That usually align with the contract BOQ structure. Once you have the high level setup then you breakdown to the next detail level ..... until to the level that you are setasify or unable to break anymore. Then you have a top down estimation.

If you refer to plan Top down estimate then it is very similar but it start with WBS instead of CBS and break down the activity and establish linkage between activities. then you will have a top down estimated schedule

Good Luck

Alex
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Tue, 2007-01-16 11:21
#4
Mario Sanvitale
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Top down estimation works in conjunction with estimation weights. Essentially you organise an allocation of relative time between hierarchical levels in the WBS down to activity level. This means that a single entry of "total expected effort" can be filtered down to generate individual activity effort.

For example if a project has a total expected effort of 100 hours, at WBS level one if the split is 3:1 then 75 hours will go to the first leg and 25 to the second. If the split at WBS2 for leg one is 6:9 then the 75 hours in leg one will be allocated 30:45, and so on. Confused? Only because it’s difficult to show without a diagram, it’s pretty easy really - the problem is getting the metrics to generate the estimation weights.

Function Point Estimation is a process developed by AJ Albrecht at IBM in the 70s whereby the value of the total expected effort for a software project can be calculated by reference to a combination of the complexity of outputs, inquiries, inputs, files, and interfaces within the project, as influenced by external constraints and requirements.

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