Chapter 13. Developer Productivity: Skilled Versus Average

LET'S DEBUNK SOME OF THE MYTHS about developer skills for project managers who have been assigned for the first time to software projects. Understand that really good software developers are much more productive than average ones. In fact, some statistics say that really good developers are multiple orders of magnitude better than poor ones. One order of magnitude is the same as multiplying a quantity by 10. The point is, a skilled programmer isn't just a little better than an average one; the difference is huge.
What should this mean to our newly minted software project managers as they plan the development of this product? Managers erroneously think that even if you can't get the best and brightest, you still get some usefulness out of mediocre developers. But building software isn't like digging a ditch, where even the poorest ditch diggers can make a hole.
In software development, what is programmed today becomes the foundation for tomorrow. If you have mediocre developers building your foundation, the really good developers have to go back and fix the flaws before they can move on. Hiring mediocre or average developers slows project velocity.[7] Frequently, taking a poor performer off the team is more beneficial than adding a good one.
Couple this with the fact that adding people to a late project makes it even ...