Effective Project Management: Traditional, Agile, Extreme, Sixth Edition

Estimating

Estimation is the one area where most project teams have trouble. For one thing, there is no consistency. One person might be optimistic, another pessimistic, and you won't know which unless you have had prior substantiating evidence of one or the other. Having the professional who will be responsible for the work also estimate the duration or labor involved is a good idea, but it isn't the answer either. Will this person be pessimistic just so the work is sure to meet the estimated deadline? The approach that I use is to have more than one person provide each estimate, as explained in this section.

Estimating Duration

Before you can estimate duration, you need to make sure everyone is working from a common definition. The duration of a project is the elapsed time in business working days, not including weekends, holidays, or other non-work days. Work effort is labor required to complete a task. That labor can be consecutive or nonconsecutive hours.

Duration and work effort are not the same thing. For example, I had a client pose the following situation: The client had a task that required him to send a document to his attorney, where it would be reviewed, marked up, and then returned. He had done this on several previous occasions, and it normally took about 10 business days before the document was back in his office. He knew the attorney took only about 30 minutes to review and mark up the document. His question was, “What's the duration?” The answer is 10 days. The ...