"Adding manpower to a late software project makes it later," coined by Fred Brooks, author of "The Mythical Man-Month," published in 1975. The extra human communications required to add another member to a programming team is considerably more than anyone ever expects. It naturally depends on the experience and sophistication of the programmers involved and the quality of available documentation. Nevertheless, no matter how much experience they have, the additional time discussing the assignment, commitments and technical details as well as evaluating the results becomes exponential as more people are added. See laws.