To follow up on my previous post about estiquotes, and 37signals post on late projects: No one can predict the future, and project estimates are an educated guess at best.
In my own personal life, I find I can only vaguely predict what is happening this week. Next week’s events? I might just as easily name the date that Christ is to return. Work is no different – what I think I can accomplish for the day at 8am is wildly different than what was accomplished when I close up shop for the day.
Project planning is the same way. It is reasonably easy to predetermine a sequence of events, but identifying dates for when they will happen is largely meaningless.
You might say I just don’t have talent, or I am not thinking the project through well enough, but tell me this: when you know you have to cancel a meeting, do you know it months ahead of time? weeks? I find meetings are most often cancelled an hour before they start, and often the lead time is less than 5 minutes.
If we can’t habitually predict today’s events with accuracy, how can we possibly predict events weeks or months later?
Jason says it best
We release things when they are ready to be released, not based [on] a we-can-predict-the-future schedule.
Priorities shift, products change, new ideas bubble up, we discover new techniques and concepts, mistakes are made, external circumstances reveal themselves.
All those things make schedules a waste of time. They don’t account for surprises, new opportunities, gut feel, and human error. Schedules are too theoretical for our tastes.
The only time we start thinking about dates are when we’re really close to release. Then we can say “let’s try to get this out next Monday” or “Let’s do what we can over the next couple week and then go live with it.”