I never guess. It is a shocking habit—destructive to the logical faculty.
How long is a piece of string? Or for our purposes, how long does a piece of string take? It's as simple a question to answer, and it makes about as much sense.
This chapter is about software timescale estimation, an important skill of the professional programmer. It's one of the mystical black arts of development, based more on hunches than science, with frequently inaccurate results. It's complicated, but an essential part of the software development process, and is something that every programmer must learn to do.
The rules of the software factory ...