TOPIC: Cornelius Fichtner - Help Required

Hi Cornelius,
I had subscribe to your daily newsletters and bought flash cards also. I had a query regarding yesterdays question. As Per PMBOK guide the rough order of magnitude lies between -50% to +50%, but as per your explanation it is -25% to +75%, can you please elabourate me why? Thanks J

Your customer has asked you for an order of magnitude estimate. You estimate that the project will be around $1000. What is your response to the customer?

A.) $1000
B.) $900 - $1250
C.) $760 - $1600
D.) $1000 - $2000

C.) is correct. An order of magnitude estimate should be between -25% to +75% of the estimated cost. C is closest to this guideline.

Jasvir,

Can you please tell me what the subject of that newsletter email is? Otherwise I have to look through 48 emails to find this particular question.

Thanks!

Hi Cornelius,
Tha mail is with Subject " Learn how to estimate" dated 27 jan 2011.

Thanks

Jasvir,

We explained the reason why there is a difference right in the email itself...

Here is the explanation that we gave

If you compare these numbers to the PMBOK Guide you will notice that there is a difference. The PMBOK Guide only mentions the ROM at -50% to +50% but not the other numbers. Don't be surprised. The PMBOK Guide only contains about 75% of the knowledge required for the PMP exam. The other 25% come from various other sources and the PMI does not specify exactly from where. The percentages that we have listed above are the generally accepted ranges and you can find them references both in many PMP prep books as well as on many free PMP websites. But don't be shocked if they are not in the PMBOK Guide.