[consulting] Estimation-Blowout case-studies wanted

[Ben West]

Predicting the future is indeed a hard trick to pull off each and
every time.  ;)  This task is especially difficult for freelancers who
have concern about particular projects requiring more hours than their
client is willing to pay for.

I'm not sure if there can ever be an overall methodology for
predicting hours spent, but there are always some common-sense
inspired points to keep in mind, e.g

- How many person-hours did a similar job require in the past, e.g.
upgrading drupal.org from v4.7 to 5.0?

- Were many hours spent debugging items like usability and browser
compatibility?  For my estimates, I try to give very rough guesses for
time spent on usability and browser issues as additional line items,
using values like 1hr per each unproven module or 30min per each page
built from scratch.

- What some people call "padding hours" I tend to call "guard band."

- What are actual milestones to "completion" and/or satisfaction of
the client?  If these 2 things are not actually identical, then there
is possibility for feature creep to increase the # of hour spent.

On Fri, Feb 20, 2009 at 8:34 PM, John Saward <john at also.com.au> wrote:
> 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
>
> ==============
> John Saward
> www.drupal.com.au
> 03 5968 1541
> ==============
>
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-- 
Ben West
westbywest at gmail.com