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PMP Q- Time

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Mahfuz
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PMP Q- Time

Sat Dec 12, 2015 10:08 pm

Backward pass benefit?
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Kind regards,
Mahfuz Rahman ,PMP
sunildubai15
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Re: PMP Q- Time

Sun Dec 13, 2015 5:12 am

Backward pass always done for negative slack. looks to me A
Mahfuz
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Re: PMP Q- Time

Sun Dec 13, 2015 7:48 am

wrong answer Sunil!
Kind regards,
Mahfuz Rahman ,PMP
manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 8:00 am

backward pass determines the latest times an activity can be started and finished without compromising the timing of the project as a whole while it also helps in understanding which activities are on critical path(s) so it can be B or C
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Manish P
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http://www.izenbridge.com/blog/7-effect ... ification/
Mahfuz
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Re: PMP Q- Time

Sun Dec 13, 2015 8:13 am

I had confidently answered C but per source it is B. I did not get an explanations. I am stopping all these free tests! Back to notes and books!
Kind regards,
Mahfuz Rahman ,PMP
manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 8:41 am

:) but i hope you did understand the concept of backward pass
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Manish P
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sunildubai15
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Re: PMP Q- Time

Sun Dec 13, 2015 10:24 am

Thanks Manish
Somewhere while giving some practice exam, i found this answer.
nice explanation
ujjal_show
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Re: PMP Q- Time

Sun Dec 13, 2015 11:10 am

the answer should be only B.

please look at the question " important to identify & evaluate" its pointing to positive slack.
identifying "no slack" will not give any benefit to Pm
manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 11:41 am

Hi Ujjwal.

Unless u do Backward pass you cannot determine Critical path, i.e once backward pass is done you also know activity with 0 float
you also need to evaluate activities with 0 float in case
- there are multiple critical paths and need to evaluate option to reduce critical paths
- activities on critical path also needs to be evaluated for resource security, risk management etc

so we cannot zero down only on B
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Manish P
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ujjal_show
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Re: PMP Q- Time

Sun Dec 13, 2015 2:05 pm

manish with due respect I'm strongly deny this statement..
Unless u do Backward pass you cannot determine Critical path
what is the definition of critical path, The sequence of activities that represents the longest path through a project, which determines the shortest possible duration.
and to determine the "critical path" no backward pass is require, further all activity on critical path having "0" float.

now to calculate how much float is available, we need backward pass.
manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 4:32 pm

how will you calculate float on each activity with knowing late start or late finish
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Manish P
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ujjal_show
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Re: PMP Q- Time

Sun Dec 13, 2015 5:30 pm

yes manish that is I am also saying. Backward pass is need to calculate the activity which having some float.

but no backward pass calculation is require to know which activity having ZERO float... they can be identify straight away, because they are on critical path.
Last edited by ujjal_show on Sun Dec 13, 2015 5:32 pm, edited 1 time in total.
manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 5:31 pm

sorry did not get your statement
'but no backward pass calculation is require to know which activity having ZERO float... they can be identify straight away, because they are on critical path.'
unless you know ls or LF e cannot know which activity has 0 float, and only backward pass can help you with LF or LS
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Manish P
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ujjal_show
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Re: PMP Q- Time

Sun Dec 13, 2015 5:52 pm

Let have an example:

Here the critical path is ABG & ABCD.
and without calculating the backward pass, straight away we can say the activity A, B, C, D AND G having ZERO float - because they are on critical path.
now correlate my previous statement.
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manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 6:37 pm

Its not so straightforward when you have hundreds of activities with multiple relationships like SS, FF and SF with leads and lags
try some of these without a backwards pass
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Last edited by manishpn on Sun Dec 13, 2015 6:44 pm, edited 2 times in total.
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Manish P
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manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 6:40 pm

One more these are still simpler you can have SND with few hundreds of activities
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Manish P
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http://www.izenbridge.com/blog/7-effect ... ification/
ujjal_show
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Re: PMP Q- Time

Sun Dec 13, 2015 7:52 pm

manish you still you didn't get my simple logic.
regardless of complexity you can find the critical path with FORWARD PASS only.
and when you identify the critical path you also find the activity which are on critical path.
now these activity having ZERO float -no BACKWARD PASS is needed.

Activities on critical path always have ZERO float regardless of big & complexity.
manishpn
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Re: PMP Q- Time

Sun Dec 13, 2015 8:13 pm

ok :) I give up .

You can calculate total project duration or duration of your SND using forward pass , but not which activities will be on critical path,
that is only determined by calculating float on each activity which is either LS-ES or LF-EF.
Identifying activities is 0 float is equally important as PM has to put additional monitoring on such activities.

how can u determine float on each activity (for which you need LS or LF) using fwd pass please help us with example
Last edited by manishpn on Mon Dec 14, 2015 1:09 pm, edited 2 times in total.
Br,
Manish P
PMP, PMI - ACP, SAFe Agilist
http://www.izenbridge.com/blog/7-effect ... ification/
Mahfuz
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Re: PMP Q- Time

Mon Dec 14, 2015 4:21 am

Thank you both of you

Ujjal and Manish- please let's get back to the point. clear from explanation above for the benefit of forward pass. Based on this Q, What will be the benefit of backward pass in regards to first 3 options?
Kind regards,
Mahfuz Rahman ,PMP
manishpn
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Re: PMP Q- Time

Mon Dec 14, 2015 7:01 am

manishpn wrote:backward pass determines the latest times an activity can be started and finished without compromising the timing of the project as a whole while it also helps in understanding which activities are on critical path(s) so it can be B or C
so backward pass helps you with calculating float and also identifying which activity(ies) (with 0 float) will be on critical path

Hope thats clear
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Manish P
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