Buffer Types

________ is typically not referred to as a buffer type in critical chain project management. 

  A. Resource buffer
  B. Free buffer
  C. Feeding buffer
  D. Project buffer

Can anyone please answer the above?

cnppmp's picture

Free Buffer is the right answer.


You do not get such information anywhere in the PMBOK or RITA book. But you can find in Rajesh Nair notes, which mentions about Feeder buffer and project buffer only..

This buffering is related to Critical Chain Method. I'm not sure this question buffer has been asked in recent past. I know this question is from Oliver Lehmann 75 questions.


CN Patil

Yes..Feeder buffer and project buffer is in PMBOK..but have never seen of resource buffer anywhere :(

Ok..again need clarification on the below from Oliver 75 qs

In order to speed up a project, you made a decision to fast-track a phase currently performed with five team members, and another one which was planned to begin in four weeks time with another five team members.
Which of the following activities should you do first?  

A. Make sure that all exit criteria of the consecutive phase have been met to ensure the flow of communications in a team situation which is more complex by a factor of 2.
B. Make sure that all entry criteria of the previous phase have been met by planning and performing a phase gate meeting to assess technical aptness.
C. Make sure that all exit criteria of the previous phase have been met by planning and performing a phase gate meeting to assess technical performance.
D. Restructure your team and delegate tasks in order to ensure the flow of communications in a team with the number of communication channels increased by a factor of 4.5.

The answer is D..but the N for the number of communication channels for current pahse will be 5+1 (proj manager) rt? so it will be 6*5/2 ?

cnppmp's picture

this question is more related to Integration management / Phases, Iterative, Overlapping concept.

The question is about fast tracking (Schedule comprssion) and two phase with 5 resources in each phase would be working. So it is speaking about the overlapping of the phases, so you need to work on the resource restructuring since once you complete the previous phase you would be working parallely on next phase were resources needs to be adjusted based on the requirement in next phase (could be design, conecptual).

Secondly, I would calculate it has

5+5=10, so Comm Channels 10*9/2= 45

45/10 people

4.5 times



CN Patil


Restructuring the team is fine..

but for comm channel, Rita says it will be 5+5+1 (project manager) = 11 .

So comm channal 11*10/2  when fast tracking 

and no of resources will be 5+1 = 6 and comm channel will be 6*5/2 for phase 1 only?

cnppmp's picture

You are correct, but sometimes we need to use stakeholders with an assumption project manager is already considered and try to match the answer with the formula correctly applied.

Definitely such questions would take more time to answer in real exam if it appears.



CN Patil

Critical Chain Project Management is getting wide spread recognition. Paradigm shift from PERT approach for effective Project Management. A nice concept and extension of Theory of Constraints introduced by Goldratt.



Questions like these are what is causing hesitation in me to take the exam and think that i am not adequately prepared. Will the actual PMP exam be full of questions like these? Any help on this is appreciated. Note that i am not asking people to reveal the exact questions knowing fully well about PMI professional standards but just the kind of questions to expect in the exam so that i am adequately prepared. Many thanks in advance to responses.

cnppmp's picture

Do not get bothered due to such questions, you have to look at the brighter part of it, is there would be around 100 odd questions you would be able to get through quickly. Situational questions are always mind boggling but you have to get through. You need to make judgement on situational question is really going to take more time, then pick one answer go ahead do not spend more than 2 minutes on such hard questions as not all situational questions would be so hard could be around 5 to 10 questions or soemtimes it would be 15 questions.

You have to get through 106 questions correctly out of 175, so you have bigger & brighter chance of getting through the PMP Exam subject to you have done your studies well and you are thorough.

Do not get worried or bothered by one such question which you have encountered in some mock test exams. These are always much tougher tha n real PMP exam.

All the best...go ahead and take the exam..


CN Patil


Mr.Patil - Your prompt response is very encouraging and motivating. Many thanks. I am scheduled to take the exam in couple of weeks from now and will keep this in mind whenever i come across those kind of questions. Many thanks, once again. Really nice of you.

 Mr. Patil - many thanks for boosting my confidence which is very much needed for taking the PMP exam. I took the exam on 27th June and cleared with 3 Ps and 2 MPs in closing and initiating. I must definitely thank you for that. May God almighty bless you with a great career.

Planning for PMI ACP in 2-3 months, after this confidence booster.




cnppmp's picture

Hey There!!!...Great News...

Thanks for such a encouraging comemnst about me and acknowledging my suggestions..


CONGRATLUATIONS!!! and Good luck for your ACP exam...



CN Patil

You can read the following article for help in answering your question-
Critical Chain Project Management