“The Mythical Man-Month: Essays on Software Engineering” is a book by Frederick P. Brooks, first published in 1975 by Addison-Wesley. It collects essays on the management of large software projects, drawn largely from Brooks’s experience leading the development of IBM’s System/360 hardware and its OS/360 operating system.
The book’s central theme is that software projects fail to meet schedules not for lack of effort but because of the nature of the work. Its best-known argument, summarized as Brooks’s Law, is that adding people to a late project makes it later. Brooks attacks the assumption that effort can be measured in interchangeable “man-months,” showing that communication and training costs grow with team size.
Other essays cover ideas that became part of the field’s vocabulary: the value of conceptual integrity in a design, the “surgical team” model of organizing programmers, the “second-system effect” in which a designer’s follow-up project is overloaded with features, and the warning to “plan to throw one away” because the first build of a system is often a prototype.
The 1995 Anniversary Edition added Brooks’s 1986 paper “No Silver Bullet” and his later reflections. Decades after publication the book remains a standard reference in software engineering, repeatedly cited for observations about people, schedules, and complexity that newer tools have not erased.