What it argues
Frederick Brooks managed the development of OS/360, IBM's operating system for the System/360 mainframe, in the early 1960s. It was one of the largest software projects undertaken to that point, and it was very late, very over budget, and enormously complex. The Mythical Man-Month is his account of what he learned from that experience — an account specific enough to still be accurate and influential fifty years later.
The title essay establishes the book's central argument: adding manpower to a late software project makes it later. This is not intuitively obvious. If two programmers can write a program in six months, ten programmers should be able to write it in one month — but they cannot. The reason is that software development is a complex coordination task, not a simple parallel one. Adding people requires training, communication overhead, and the partitioning of the work in ways that may not be possible given the dependencies in the design. Brooks's formulation of this has become Brooks's Law: adding manpower to a late software project makes it later.
What it gets right
- 1.
Brooks's Law: adding manpower to a late software project makes it later. Communication overhead and training costs swamp the productivity gain from additional workers.
- 2.
The second-system effect: engineers building their second major system tend to over-build it, adding all the features they held back from the first. Restraint on the second project requires conscious effort.
- 3.
Conceptual integrity — a coherent underlying design vision — is the most important quality of a large system and requires concentrated authorship, not design by committee.
What it covers
Who wrote it
Frederick P. Brooks Jr. (1931–2022) was an American computer scientist who managed the development of IBM's OS/360, one of the most ambitious software projects of the 1960s, before joining the University of North Carolina at Chapel Hill, where he founded the computer science department and spent most of his academic career. He received the Turing Award in 1999 for his contributions to computer architecture and software engineering management. The Mythical Man-Month was first published in 1975 and expanded with the essay "No Silver Bullet" in a twentieth-anniversary edition in 1995. His later books include The Design of Design (2010).
