Have 2 experts make independent estimates (or one expert estimate it twice).
- Add the 2 estimates together. If the experts used different units of measurement, use the higher of the two
- Round to the next higher unit of measurement as follows:
- Minutes round to hours
- Hours round to days
- Days round to weeks
- Weeks round to months
- Months round to years
- Years round to careers. The project will terminate this many project manager’s careers before being cancelled.
Sadly, this seems to be the estimating technique on many projects. Fortunately, we now have many proven project estimating methodologies available to us.
See our posts on estimating techniques: