A common problem with software development project management is that most people don’t really understand how it works. Programmers are often likened to construction workers. Managers view them as skilled labour, like a carpenter or brick-layer. If you want something built faster, you hire more people, and things go quicker.
Software engineering is a different beast, though. Fred Brooks wrote The Mythical Man Month in 1974, and it is often considered the “bible” of software engineering. In the book, he explains how creating software is different.
Brook’s Law states that “Adding manpower to a late software project makes it later.” It’s important to keep teams small and agile, especially in the early stages when the architecture is in flux.
Creating usable, high-quality software takes a lot of time, skill and experience. Trying to cut a deadline by adding more people will almost guarantee the opposite effect.