Some things to clarify

 Hello all,

I'm styudying for PMP exam and i have some things that i want to make them clear, please help me with your knowledge:

1. I saw on Rita and on Kim Heldman book PERT and three point estimate. PERT divide everything by 6 and multiply most likely value with 4 and three point estimate divide everything by 3. How should i know in what situations to use them?

2. What roles is playing the PM during project initiation,planning and executing? ex: coaching,directing.

3. There are a lot of questions that are saying a change request has occured. What are the steps to apply when a change request occurs? Some books say that first step you evaluate the impact then document a change request, and others first document and then evaluate impact...i'm kind confused with this, can you give me some tips to know for sure how to think about these questions?

4. I read Rita 's book and then passed a little bit on Oreilly Head FIrst. At the critical path chapter i saw on Oreilly that at the first activity he puts 1 as the early start time,and on Rita she explains this one like this: if an activity doesn't have a predecessor and it's the first activity after start it has ES value 0. Who's true?

5. If i have the critical path already calculated with float and everything, how do i calculate the total float on the project? I sum up the float values that are not on the critical path? 

Thank you , i hope you can help me with these gaps.

Have a nice day!

1. three point estimate divide everything by 3

Where do you see that? I have not seen any formula that divides by 3.

2. The order is Directing, Coaching, Facilitating, Supporting.

In the initiation phase and initial planning the PM acts as a director. In late planning and early execution he takes on the coaching role. Once the team has jelled up wel and is performing without much help from PM, then the roles changes to Facilitating and ultimately to Supporting.

There should be enough information provided to help you guess what kind of role PM is taking.

3. These are trick questions. You have to read the question well to figure out what has already been done and what needs to be done next in the Change Control procedure. If the change is already documented, then next step is evaluation.