Estimating Time, Costs, and Resources
Once the work is broken down, you can estimate how long it will take. But how? Suppose I ask you how long it will take to sort a standard deck of playing cards that has been thoroughly shuffled into numerical order by suit. How would you answer that question?
The most obvious way would be to try the task several times and get a feeling for it. But if you didn’t have a deck of cards handy, you would probably think about it, imagine how long it would take, and give me an answer. People generally give me answers ranging from two minutes to ten minutes. My tests indicate that about three minutes is average for most adults.
An estimate can be made only by starting with the assumption that a certain resource ...