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To calculate freefloat

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ramkisr
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To calculate freefloat

Postby ramkisr Wed Jun 04, 2014 9:56 am

[url][/url]Please help in calculating free float of Activity A in the attached diagram.
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sunku65
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Re: To calculate freefloat

Postby sunku65 Wed Jun 04, 2014 1:07 pm

Activity F has 6 days Free Float
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Re: To calculate freefloat

Postby harin4627 Wed Jun 04, 2014 3:57 pm

Free Float: Predecessor activity can be delayed without affecting the early start date of successor activity. Here A can be delayed by 2 days without affecting the successor activity E (E starts after 7 days since depended on finish of B). So free float is 2 days. Am I correct? :?
ramkisr
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Re: To calculate freefloat

Postby ramkisr Wed Jun 04, 2014 4:02 pm

I've araised the same no. as 2. But as per source, it says that Free Float for Activity A is '0'. I got confused.
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Re: To calculate freefloat

Postby ramkisr Wed Jun 04, 2014 4:47 pm

Is it 1 for free float for Activity A?
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 3:24 am

Which Activities shares common successor activity has Free Float.
Toal 8 paths (not mention here, only critical path)
Crinical Path = START-B-D-G-H-Finish= 24 days
Free float is different from Float/Slack

Activities Float/Slack of B,D,G,H = 0 (on critical path)

No Activities has Float/Slack.

Activity A's free float = ES of E-EF of A-1 = 8-5-1= 2 days on path Start-A-E-F...
Activity F's Free float = ES of H - EF of F -1= 21-16-1=4 days on path ....F-H-Finish
Activity C's Free Float = ES of I - EF of C -1=17-9-1 = 7 days on path Start-A-C-I-Finish
Activity E's Free Float = ES of F - EF of E -1=14-12-1 = 1 day on path ...F-H-Finish
M L Dahima
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Re: To calculate freefloat

Postby M L Dahima Thu Jun 05, 2014 3:44 am

please refer attached calculation.Free float for A is Nil.
EF for A is 5 and ES for C is 6.C has to start next day because there is FS relationship between A &C.
But if you talk about just float for A then this is 7.
Saket, Any comment on this understanding pl.
thanks
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Re: To calculate freefloat

Postby saket Thu Jun 05, 2014 3:49 am

I just looked at the diagram made by ML Dahima , and its clear A is having Zero Free Float... free float are usually seen when the successor activity is also depended on something else then this predecessor.

If the relationship between A and C was not present then A could have free float
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Re: To calculate freefloat

Postby harin4627 Thu Jun 05, 2014 4:16 am

good lesson for me...don't jump into conclusion without considering multiple relationships....I completely ignored a-c relationship. always better to draw complete diagram with forward and backward passes and answer :x
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 6:27 am

I drawn same as Dhaima.
Din't get a chance to post in time.
Its confusing free float.


Hi Dhaima
Can you tell me one thing Activity A's early finish is 5 then the successor activity E's Early start is 8.
In this case the activity A has to wait 2 days, then start on 8th day on activity E, Is it not free float of Activity A.

Can you tell me any activities has free float other than Activity A. Then, i will figure it out where i am going mistake.

Thanks,
Lax
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Re: To calculate freefloat

Postby namita Thu Jun 05, 2014 6:43 am

@Lax,

Just to answer your question, A is connected to both E and C. We can't decide on A's free float by only looking at E. All the successor activities has to be considered and there should not be any successor activity which is starting the very next day.

Activity E and C are having free float because there is only one successor activity for both and ES for that is later than next day of EF of E/C activity.

Feel free to ask any further question

ML is our Critical path & float KING :)
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 7:09 am

Thank God!

I got cleared every thing on Free Float.
At least, 50% free float activities correctly solved ( i.e. C and E ) by me in above posted reply.

Thanks namitha,

Best regards,
Lax
ramkisr
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Re: To calculate freefloat

Postby ramkisr Thu Jun 05, 2014 7:10 am

adding comments to further discussion...

Since A is connected to both E and C, whether we should consider Maximum ES of E & C - to calculate Free float of A
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 7:15 am

Finally the Activity Which one has totally rest before ES of successor activity all the way(even single or multiple ways).
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 8:49 am

Hi Dahima and Saket,

Again i got question. Can you clear any one of them regarding free float.

In another website saying different(please refer fully) including comments):

http://pmstudycircle.com/2013/03/total- ... ree-float/

I questioned in that forum on 9th may. i got the answer from the admin as follows:

Activity has two successor activity, it have a free float only for one path which has larger early start date.

Finally, which method need to follow.

Thanks,
Lax
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Re: To calculate freefloat

Postby namita Thu Jun 05, 2014 9:25 am

Dear Lax,

As per PMBOK (r)..

free float—the amount of time that a schedule activity can be delayed without delaying the early start date of any successor or violating a schedule constraint—can also be determined


I would like to emphasis on ANY part of this definition
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 9:54 am

HI Namita,


free float—the amount of time that a schedule activity can be delayed without delaying the early start date of any successor or violating a schedule constraint—can also be determined.

Compare this to our Network Diagram:

In case Activity A:
The amount of time(2 days) that a schedule activity (A) can be delayed (on ..E-F..Path) without delaying the early start date of any successor (C).

Please Can you clarify!

Thanks,
Lax
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 9:56 am

Hi Namita,

Did you see the above link and comment.

Thanks,
Lax
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Re: To calculate freefloat

Postby namita Thu Jun 05, 2014 10:08 am

Dear Lax,

To understand this, think a practical situation. E.g. you have an activity to gather requirement (Say Activity A) and 2 following activities Analysis (C) and Design (E) which can start after A is completed. However the relationship is such that analysis has to start immediately after requirements are gathered where as Design can be started 2 days later

In this scenario, is there any chance you can delay completion of your requirement gathering activity without impacting analysis? even though you can start design later? No we can't. Therefore practically if we have even one activity which is starting immediately after current activity we can't delay the current activity.

On paper activity A may be delayed for activity E but practically its not possible without impacting activity C
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Re: To calculate freefloat

Postby sunku65 Thu Jun 05, 2014 2:02 pm

Thank,

So, finally i stick with this method.
The method in the PMstudycircle is ignored.

Thanks,
Lax
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Re: To calculate freefloat

Postby saket Fri Jun 06, 2014 12:53 am

@sunku65

I could not go though the complete thread from the other website but i do agree with Namita has explained. for free float rather than formula we need to look at how the next activity is getting impacted with delay.... if no impact to anyone then only we can say this free float for given activities.

Free Float. The amount of time that a schedule activity can be delayed without delaying the early start date of any
successor or violating a schedule constraint
.


Can we any way link the concept of having path level free float with the definition of free float? we can not, i have never come across anyone thinking about path level free floats , we do not have such concept.

Lets try some more questions if you have , please post them as separate threads :)
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Re: To calculate freefloat

Postby sunku65 Fri Jun 06, 2014 6:21 am

Hi Saket,

According to Namita's post cleared everything. My main intention is other website's method.
Care fully compared with the starting date and finishing date of the activities instead of days.
Then i got cleared everything. Finally concluding other website method is wrong.

Thanks,
Lax
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Re: To calculate freefloat

Postby saket Fri Jun 06, 2014 8:08 am

Great @sunku65
Do share if you have more such confusing questions :)
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Re: To calculate freefloat

Postby hi2shrads Mon Jun 09, 2014 5:03 am

Guys,

Interesting thread. There are certainly some questions related to FF and SS relationship in placed and asking for lead and lag etc.

Shraddha

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