Help me to clear the concept of duration uncertainty
Submitted by pkpmp on Thu, 04/10/2014 - 06:39
The following duration uncertainties are all calculated assuming a ±3sigma confidence interval. The duration uncertainty—defined as pessimistic minus optimistic estimate—of the first activity is 18 days; the second estimate has an uncertainty of 24 days. Applying the PERT formula for paths, what is the duration uncertainty of the entire path?
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admin
Fri, 04/11/2014 - 10:23
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Where is the diagaram?
Where is the diagaram?
pkpmp
Fri, 04/11/2014 - 11:01
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No diagram was there
....
philstinnet
Sat, 04/19/2014 - 18:18
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Assuming that activity A and
Assuming that activity A and B enjoy 'Finish-to-Start' dependencies. The duration uncertainity of the entire path should be 30 days.
What is the answer ?
Thanks
signor_rk
Mon, 08/11/2014 - 06:30
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Considering the activities are in serial
hi friends,
Please find the solution as follows:
Activity ....(P–O)Duration .....Sigma .....Variance
A .... 18 .... 18/6 = 3 .. 3*3 = 9
B .... 24 .... 24/6 = 4 .. 4*4 = 16
Variance sum = 9 +16 = 25
Over all Sigma = √Variance
= √25
=5
So the duration uncertainty for the entire path
= 6* Overall Sigma = 6*5 = 30 days
(Solution source can not remember) Thanks & regards,
Ranjit