Critical path - need clarification

Dear All,


Would like to get clarfied on Critical path calculation method:


Out of the two methods given below, which one we should use to calculate Critical path, if given in exam:


1. Calculate critical path by finding the path with longest duration


(as per Rita Mulcahy "the path wth the longest duration is the critical path)


or


2. First calculate the float of all the activities. Find the path/s with zero / less float and find the length of 


duration for each of those paths. The path with longest duration (out of the paths with zero / less float) is


the Critical path


Please give the explanation for your suggestions.


Thanks


Srikrishna

#1 is the only approach.  In general, in a network diagram, you can not calculate float on each branch unless you know the critical path ( the branch with the longest duration)

 

Chandra

First method is easy one and mostly there in exam.


Second method is lengthy one and one have to find ES,EF,LF,LS through network diagram and than get the float. Zreo (or negative) float indicates task on critical path.


For exam purpose you need to learn both. Practically, scheduling software does all tthis things once you put activity, durations and sequencing.


PMP King

The PMP Guru's picture

There are Two Kinds of Diagrams:

The Simple Diagram's.

The Detail Diagram's.

The above is my own interpretations and you may not find it anywhere else, As I Couldn't find the exact wording for calling these Diagram's, So I call them Simple and Detail.

In The Simple Diagrams, You are not given the ES,EF,LS,LF while in the detail Diagrams you are given all those.

In Simple Diagrams: The Duration is given and you simply need to Add all the durations on the paths and finds your Critical path with the longest duration.

In Detail Diagrams: If you are given the Durations, Then as with the Simple Diagram's you add all the durations on the paths and finds your Critical path with the longest duration. If Duration for an activity is not given then you have to find it through the ES,EF,LS,LF and then do it as described above.

I made some Videos (Critical Path, Float etc) which will hopefully be beneficial for all, Please check and if there still something that's not clear. You can always put your comments and I would love to answer them.

http://thepmpguru.wordpress.com/category/video-tutorials/

Kind regards,

The PMP Guru

http://thepmpguru.wordpress.com/

 

 

Thanks everyone for the clarification


Thanks


Srikrishna