yes the definition in the glossary is fine and has more precedence and it doesn't contradict with the one in page 253.

the thing is both A and B have some limitations, A limits the source of lessons learnt to the team and B limits it to customer. while D is more generic, analysis of the variance can be done by both the team or with the customer.

I am still in favor of D as the best answer .

Not so quick there guys - yes I see what it says on page 253, however I also see what it says on p254, 303, 389, 409, 415 which are all different. Furthermore if we want the PMBOK official definition to get unconfused then the authoritive answer would be naturally found with the glossary.

The glossary defines Lessons Learned as: The knowledge gained during a project which shows how project events were addressed or should be addressed in the future with the purpose of improving future performance.

Now by definition the glossary takes precedence over all of the other various references in the book - it is the definitive definition so to speak.

So I conclude that per the definition Nishant's answer is perfectly correct. In fact since it directly addresses the PMBOK definition it is the best of the two possible correct answers.

And anyway - how ridiculous is it to have one official definition and then no less than six different other descriptions of the item throughout the book. So I conclude that the answer given is invalid since even if D is true B is also true (and indeed more true, so if you have to pick one answer it has to be .

Tracey and Ahmed nailed it.

If you look at each of the other possible answers, you will notice a theme that while they seem plausible, they do not align with the definition of what Lessons Learned should 'include':

(a) The collective wisdom of the team: (Wisdom does not explain cause of variance, nor does it imply a lesson learned)
(b) Feedback from customer as to what you could have done better (Feedback from the customer is valuable, but that feedback didn't state variance as a context.)
(c) Information to be used as an input into administrative closure (This is outright wrong)

Hi Nishant,

Please refer to the definition of the lessons leared in PMBOK 5th Edition page 253 as below. while answers A and B may be correct and are some sources for lessons learned; however the best answer is D as both the team and customer feedback will be based on observing and analyzing variances.


"Lessons learned documentation. The causes of variances, the reasoning behind the corrective action
chosen, and other types of lessons learned from control quality are documented so they become part of
the historical database for both the project and the performing organization."

Ideally should have no variance if all is going as per plan. But variance occurs so analyze them and record as lessons learned for future reference.

Hi Nishant:

Here is the definition of Lessons Learned that I use: The formally documented information the team has acquired during the execution of the project. Lessons learned specifically focus on variances in the project and document how the team would plan or execute differently if they had a specific component of the project to perform again.

With that definition, D would be the better choice over B.

Tracey