Predicting effort.
WHY ESTIMATES ARE WRONG
The unknowns are discovered during the work, not before.
WHAT MAKES THEM BETTER
Breaking work into small pieces Basing them on similar past work Stating assumptions Giving ranges rather than single figures
WHY A RANGE
A single figure implies a precision that does not exist.
WHAT TO INCLUDE THAT PEOPLE OMIT
Testing Code review and revision Deployment Documentation Coordination and meetings Fixing defects found
WHAT RELATIVE ESTIMATION PROVIDES
Comparing pieces of work to each other rather than estimating hours.
WHY IT HELPS
People compare more accurately than they predict.
WHAT TO TRACK
Actual against estimated.
WHY
It is the only way estimates improve, and it reveals a consistent bias that can be corrected.
WHAT TO NEVER DO
Estimate under pressure Estimate something you do not understand Allow an estimate to become a commitment without saying so
THAT LAST POINT
An estimate is a prediction. A commitment is a promise. Confusing them causes most schedule disputes.
