A manager went to the master programmer and showed him the requirements document for a new application. The manager asked the master: "How long will it take to design this system if I assign five programmers to it?"
"It will take one year," said the master promptly.
"But we need this system immediately or even sooner! How long will it take if I assign ten programmers to it?"
The master programmer frowned. "In that case, it will take two years."
"And what if I assign a hundred programmers to it?"
The master programmer shrugged. "Then the design will never be completed," he said.
Excerpt from The Tao of Programming, Book Three