Estimations on software

Software estimation is difficult, and what some people try to do with software estimation isn’t even theoretically possible. Upper management, lower manage-ment, customers, and some developers don’t seem to understand why estimation is so hard. People who don’t understand software estimation’s inherent difficulties can play an unwitting role in making estimation even harder than it already is. (…) The basic software-estimation story is that software development is a process of gradual refinement. You begin with a fuzzy picture of what you want to build and then spend the rest of the project trying to bring that picture into clear focus. Because the picture of the software you’re trying to build is fuzzy, the estimate of the time and effort need to build it is fuzzy too.” (p. 165)

On project visibility, and related to Data methodology:

No trade-off between development time and defects: