Someone please help me on this network diagram concept:

 Someone please help me on this network diagram concept:

While developing network diagram HeadFirst book adds 1 day while moving forward from one activity to other

so, ES of B = LS of A + 1. Subtraction happens on backward

Rita assumes ES of B = LS of A.

I always make wrong answer to these questions when it should be an easy catch.


Thanks in advance,


Its a most debateble topic.

What I feel PMP exam will give the numbers and then will ask you soemthing on it. I dont think they will give any ambiguos question that has 2 ways of solving it.




 Rita, PMStudy, Villanova materials all use 0 

 Hi..pmbok 5 has shed some more details on it. I feel first method makes more sense as it matches with how we creates project plan. Can you pls post those questions where you are  getting wrong choices. Then we can discuss more on them particularly .

can refer

Which method should we use on PMP exam? zero or one day?

Hello  Pawarjee,

I have a question regarding ES EF LS &  LF questions

you mentioned in the forum that in exam to follow 0 method.

If there are 2 options for 0 and 1 then to go for 0 method.

I want to know  did you get this kind of questions in exam

where both the ans were  present that is 0 and 1 method.

Pls let me know.




S S Pawar <>

No, so far not asked Like such.


Examiners know better this fact than us.

So Generally you will not find any complexity.

Though in case you find both options without any
indication of which method has to follow then
you may prefer 0 start method.
A PMI community says to adopt 0 start method. You may refer that article in my blog -
Now PMI also clears in PMBOK 5, as follows:

Figure 6-18--Added the following clarifying the note to the figure. This example uses the accepted convention of the project starting on day 1 for calculating calendar start and finish dates. There are other accepted conventions that may be used






if you are really following many posts based on 0 and 1 start methods/or my blog and then will analyse , q 106, you will not ask it.

Thanks for sahring the discussion and links but I am still not sure what would be the correct answer if this question appears on th exam.