Ever bet on a horse race? Me either. But, I’m sure you’re aware of odds. Odds-makers describe the chances of everything. What are the chances a horse will finish first, second, place, etc. Horses with long-shot odds pay out better than horses with good odds. Why? Because in order for you to get a big win, you have to bet on a rare event, like a lame, old nag winning the race. Something that nobody predicts is going to happen.
Even when odds-makers give a horse good odds of winning there is no guarantee that the horse will win. If there was, betting on horse races will be silly and pointless. If the outcomes were always known, there would be no big wins to be had.
This is generally true of all statistics. Statistics refer to the odds of an event. When some report says “people who smoke have a 150% increased risk of developing cancer” (I’m making those numbers up) they are talking about the odds. I’m sure you know someone who smoked their entire life and never got cancer. Fact is, nobody debates that the odds were against them… except the smoker, who says “look at me, I smoked my entire life and nothing bad ever happened to me!”
It may very well be true. But that person only experienced one lifetime. If they had to do their life 100 times over, the odds are that they’d more likely than not develop cancer. When we have software projects, the same holds true. If we understand factors which are more likely to result in project failure (like not having a risk management plan), there is no guarantee that the project will fail. In fact, many times it will succeed, and remembering that, people won’t change their behavior.
But (assuming your data is good), over the long run, projects that don’t do risk management will fail more often. Nobody may notice the project here or there, but over the long run, ignoring statistical realities means doing harm to your company that you can clearly avoid.
Unfortunately, odds also means that sometimes you will press someone to take action based on the odds, and they won’t, and things will turn out ok. They’ll use that data point to say “hah! see, you were wrong, I didn’t do my risk management plan and the project turned out fine.”
To that you should respond, “odds are not guarantees, we do these things because we improve the odds of success.” Managing the odds is what good management is about. Nobody can ever guarantee you a good outcome or a bad one. There are miraculous results, like people surviving plane crashes, that nobody can explain, when the odds are clearly against them surviving. There are also miraculous results, like projects going well, that nobody can explain, when the odds of the project going well is against them. Don’t let an unexpected success dissuade you from taking the odds into account.
In the long run, and that’s what really matters, the odds will catch up to you.