[consulting] Estimation-Blowout case-studies wanted

[John Saward]

I'm currently very interested in people's experiences with 
'estimation-blowout'.

In my experience, and discussions with Project Managers, Developers 
and Clients I find that quite often the number of hours to actually 
complete a Drupal project or task, is considerably more than the 
number of hours estimated beforehand. This creates problems 
(budgetary and otherwise) and stress and even resentments to all 
involved whether the work is being performed on a 
fixed-price-quotation, estimated or actual-hours basis.

I note the comment from the team who recently updated drupal.org from 
5 to 6, "So while we crafted a fine plan for the upgrade, it took a 
few more hours then originally planned." http://drupal.org/node/376454.

I'm understanding that the preparation and planning for the upgrade 
was a mammoth task, when I read the report of the upgrade sprint, at 
http://drupal.org/node/366562. Those at the sprint, and other 
contributors, worked hard doing all that was humanly possible to 
prepare and plan for the upgrade so that least downtime as possible 
would be entailed.  One outcome of the sprint would have been an 
estimation of how many hours would be required for the final push, 
the working time that would necessarily entail site downtime. And now 
I see that the actual upgrade was more intricate and time-consuming 
than that prediction.

My thinking is that these guys are some of the most experienced 
Drupal engineers around; and most familiar with the entire drupal.org 
infrastructure. If they are unable to predict the hours beforehand, 
even after going into 'fine planning' .... well.... who could have?

What does it take to accurately estimate a significant Drupal 
project? Experience obviously, but it seems that is not always enough 
in itself. Are there just always too many unknowns, too many 
variables, too many 'what ifs' to be overlooked, in any 
more-than-basic Drupal work?  Is accurate estimation for anything 
other than highly-repetitive tasks.... verging on the impossible?

I'm interested in hearing views and experiences about this.

And also I'm interested to know if the upgrade team has a record of 
hours predicted against actual hours taken, for the upgrade.

John

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John Saward
www.drupal.com.au
03 5968 1541
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