I have been burned more times than I can
count by bad estimates. What can a project manager do to help ensure the
accuracy of estimates? First we should understand the basics behind
the estimating process (there are many more than I have listed here). Some are:
• The
more unique , complex, or larger the project, the more of a challenge
it will be to get good estimates
•
Estimates are only as good as the estimator is at predicting the future
• "Padded" estimates are not always bad as long as the padding is
communicated (... and as long as the Project Manager is the one doing the
"padding")
• An
estimate is not a bid
•
Estimates using sound estimating practices, performed by experienced estimators
from clear specifications should never be negotiated
•
Ballpark estimates are guesses and should be treated as much by the project
team, management, and the project sponsor
Other
items to consider when estimating are:
•
Ensure the statement of work or contract is clear and understood by the
person(s) doing the estimates
•
Ensure that a schedule or mandated date doesn't drive the estimating thought
process
•
Include Risk Management in the estimating process
•
Ensure that estimates take into account the skill level(s) of the person(s)
that will do the work
• If
your work breakdown structure (WBS) is flawed, your estimates will be
inaccurate
Accurate
estimating is an art and a science. The estimator (or team) must take into
account historical data from past projects, the team's knowledge and
experience, the project risks, the statement of work and other project
information to make the best estimate possible.
Keep in
mind when planning your project that estimates aren't hard and fast numbers.
They are guesses, however they should be very good guesses if you have good
estimators and are following tried and true estimating practices.