21 Jun 2012. comments
Fred Brooks authored a book in 1975 called The Mythical Man Month. In it he argued that adding manpower to a late software project makes it later. The core of this belief has been captured in Brooks’s Law:
It takes some time for the people added to a project to become productive. This is known as ‘ramp up’ time. Software projects are complex engineering endeavors, and new workers on the project must first become educated about the work that has preceded them; this education requires diverting resources already working on the project, temporarily diminishing their productivity while the new workers are not yet contributing meaningfully.
Communication overheads increase as the number of people increases. The number of different communication channels increases along with the square of the number of people; doubling the number of people results in four times as many different conversations. Everyone working on the same task needs to keep in sync. So as more people are added they spend more time trying to find out what everyone else is doing.