You dont need to change current units. Just enter the estimated Units and click apply and it will distribute estimated unit to all resources selected using est weight.
It’s very simple. Top Down Estimation can be use with or without resource assigned to activities. It has an option to select labor or non-labor when using TDE. It will replace the units assign to resources once selected.
Ex:
Default assignment:
As per example above you can see that five activities has est weight assigned and as per default unit had been allocated using default unit/time * duration. Activity 2 & 4 has 2 resources (labor & non-labor) and Activity 5 has no resource assignment.
TDE using labor assignment:
On the next Figure you can see that TDE replace all units assigned to labor using est weight * estimated unit to prorate on activities.
TDE using labor on all activities:
On the Figure above, using TDE without selecting resource, all units will be prorated against est weight * estimated units to all activities with or without resources. If you will check the status tab-> Labor Unit on Activity 5 you will notice that 10 units have been allocated even no resource assigned to activities. If you will look on Resource spreadsheet on above figure, 90 units have been allocated to labor Internal/ Award but on the activity column it has 100 units under Budgeted Labor Units.
TDE using non-labor assignments:
It will be the same process for non-labor.
For materials using TDE requires individual material resource to be selected only.
That is normal to have the unit equivalent to durations * hours per time period when first assigning resources to activities. That will be overwritten by TDE once calculate unit using TDE base on activity weight proportion.
If you are using Task dependent activity, it is not recommend to use Fixed Units or Fixed Unit/Time duration type as it was a recommended to Resource dependent activity which commonly used for resource driven activity.
For Task dependent it is recommended to use Fixed Duration and Unit or Fixed Duration and unit/time except for especial purposes.
Member for
7 years 6 monthsHi ShaziaBelow article may be
Hi Shazia
Below article may be useful for top down estimating
https://www.projectcubicle.com/top-down-estimating-in-primavera-p6/
Member for
15 years 8 monthsHi,I write an article
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/
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Dear Sir
Thanks so much.
now its worked .
Best Regards,
Member for
19 yearsRE: TOP DOWN ESTIMATION P6-v7
Shazia,
If all the resources assigned are Labor, dont select any resource and just select labor then enter estimated units and click apply.
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Dear Sir.
Sorry, the email bounce back due to big file size.
Please advise me how to use TDE with Multiple resource,
I mean 4 activity , and 4 diffrenet resource,
Kindly send me Scrren shot if you have done.
Thanks & Best regards
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Dear Sir
Due to DRM i am not able to copy past screenshot in PP
yes i have assign resource which is all within WBS.
I Have sent email to you with all screen shot attached.
Thanks & Best Regards
Member for
19 yearsRE: TOP DOWN ESTIMATION P6-v7
Shazia,
Can you send me the screenshot so I can visualize the problem? Are you sure that the resource selected is assigned to activity within WBS selected?
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Sir
I try , P6 Mesg.
" There are Currently no activity selected for the estimate,
Please select a wbs and resource to indicate at least one activity in the estmate,"
I have select a WBS which having 5 Activity,in TDE Tab But TDE tab WBS section Displaying 0 activity,
Please advise in TDE Tab Resource section i ahve select a Resource WBS or only one resource,
Could you please try at your end with different 4 Resource for Five activity,to use TDE
Please Advise,
Member for
19 yearsRE: TOP DOWN ESTIMATION P6-v7
Shazia,
You dont need to change current units. Just enter the estimated Units and click apply and it will distribute estimated unit to all resources selected using est weight.
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Dear Sir
Thanks so much for you deatil explanation.
I have a small problem, while i am try to follow same step.
i have 5 activity, & 4 seource,
est. weight allready assign
Using TDP tab, i have tick Labour unit,
WBS-i have select activity WBS there is 5 activity and 140 current units.
Resource -while i am selecting resource i have slect Resource WBS where is 4 resource under resource tab.
Problem - IN TDE Tab Total Actvity and Current Units are 0 and deactivate means i could not enter any value.
while i am slecting only one resource than Current actvitity one and units (showing as per resource assigmnet)
TDE
I want to distribute 100 labour Units to all 4 activites with respect there wt.
Please advise me where i am doing mistake.
Member for
19 yearsRE: TOP DOWN ESTIMATION P6-v7
Shazia,




It’s very simple. Top Down Estimation can be use with or without resource assigned to activities. It has an option to select labor or non-labor when using TDE. It will replace the units assign to resources once selected.
Ex:
Default assignment:
As per example above you can see that five activities has est weight assigned and as per default unit had been allocated using default unit/time * duration. Activity 2 & 4 has 2 resources (labor & non-labor) and Activity 5 has no resource assignment.
TDE using labor assignment:
On the next Figure you can see that TDE replace all units assigned to labor using est weight * estimated unit to prorate on activities.
TDE using labor on all activities:
On the Figure above, using TDE without selecting resource, all units will be prorated against est weight * estimated units to all activities with or without resources. If you will check the status tab-> Labor Unit on Activity 5 you will notice that 10 units have been allocated even no resource assigned to activities. If you will look on Resource spreadsheet on above figure, 90 units have been allocated to labor Internal/ Award but on the activity column it has 100 units under Budgeted Labor Units.
TDE using non-labor assignments:
It will be the same process for non-labor.
For materials using TDE requires individual material resource to be selected only.
Best Regards,
Rodel
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Dear Sir
Thanks for your reply.
How to overwritten units.
if one activity having 2 resource one is Labor and other is nonlabor then , it will overwritten only labour units or both labour and nonlobor.
please provide steps for overwritten.
Best Regards
Member for
19 yearsRE: TOP DOWN ESTIMATION P6-v7
Shazia,
That is normal to have the unit equivalent to durations * hours per time period when first assigning resources to activities. That will be overwritten by TDE once calculate unit using TDE base on activity weight proportion.
If you are using Task dependent activity, it is not recommend to use Fixed Units or Fixed Unit/Time duration type as it was a recommended to Resource dependent activity which commonly used for resource driven activity.
For Task dependent it is recommended to use Fixed Duration and Unit or Fixed Duration and unit/time except for especial purposes.
Member for
17 years 6 monthsRE: TOP DOWN ESTIMATION P6-v7
Dear Sir.
Thanks for your reply.
Please advise me.
WBS-Act Weighting Distribution
-> Act1 = 10 = 50
-> Act2 = 30 = 150
-> Act3 = 40 = 200
-> Act4 = 20 = 100
after distribution how i can assign resource to Actvity.
example Act1 having 50 units regardless duration ,i have to spend 50 units to complete the task.
50 units means one resource work 5 days with 10/d Cal.
however Act1 OD is 8 days, in that case, uints calculated by primavera 10 *8 = 80 Units
This is my confusion or may be i am adopting wrong method
1.I want to use TDE option to calculate activity units with respect to Weights.
2.i want to assign resource to the activity according to theire units distributed by TDE option
3. I want update the SCH, based on Physical Progress.
This is Project Manager requirment he has fixed uints & fixed Budget.
Please advise,how i can tackle this situation and which method i can use.
Thanks and Best Regards
Member for
19 yearsRE: TOP DOWN ESTIMATION P6-v7
Shazia,
I’m not sure how you define your weightings. Top Down Estimation calculate or distribute units as follows:
Say Prior Experience Estimated units = 500 units
WBS-Act Weighting Distribution
-> Act1 = 10 = 50
-> Act2 = 30 = 150
-> Act3 = 40 = 200
-> Act4 = 20 = 100
------------------------
-> Total = 100 = 500