Monday, February 11, 2013

My concern about Story Points proved right!

This months PragPub Magazine contains a great article by Ron Jeffries called "Estimation is Evil". It contains a couple of great quotes I'd like to share, and also proves my concern about Story Points right.

In my previous post "Story Points vs Hours" about a year ago I wrote:
"The more unreasonable reason is that as estimates are hard to do, you put a metric on them that is hard to understand to get away with them easier. If you say that something will take three days it's easy to see if you were right, while estimating it will take three Story Points will keep you safe. Who are to say how long a Story Point is? Hardcore agilists laughs at such a silly question."
In Ron's article he writes:
"There are a number of ideas about how to estimate using something other than time. Points, Gummi Bears, Fibonacci numbers, T-shirt sizes. These were originally invented to obscure the time aspect, so that management wouldn’t be tempted to misuse the estimates. (I know: I was there when they were invented. I may actually have invented Points. If I did, I’m sorry now.)"
Wow! Reading that just forced me to write this post!

However, since I wrote my previous post I've had the chance to use Story Points and was pretty happy doing it. We started with the assumption of a story point being half a day. That way, when estimating, we could easily transform our estimates, and thinking about "half days" instead of hours made the estimations simpler. "Would you finish this is half a day? One day? Two days?" is more tangible and easier to answer than doing the same with hours.

The story point estimates keeps being translated to hours on another level though, and my most frequent question is what formula to use for that transformation now. That's alright with my though, I can stick with estimating in half days and calling it Story Points. I'm just not sure about the formula, is half a day 3 hours, 3.5 hours or 4 hours? We started with the assumption of it being 4 hours, but as we usually are faster than we estimate with that formula I'm about to lower it...

Well, back to the article... Here are some other great quotes from it:
"Most of us were taught to write down all our requirements at the very beginning of the project. There are only three things wrong with this: “requirements,” “the very beginning,” and “all.” At the very beginning, we know less about our project than we’ll ever know again."
"Anyone who has ever looked at a list of “requirements” has seen some items that were very important, and some that were—well—not so important. Not so important like 1/100th as important as the most important things. Not so important like downright bad ideas. There is a very strong “80-20” rule at work in requirements lists. The bulk of the value comes from a very small subset of the so-called requirements. So these other things aren’t “requirements” at all. They’re ideas, and some of them are not very good."
"It seems that “they” often want to know how long something is going to take, and how much it will cost. My view is that “they” don’t even know what they want, so we bloody well can’t possibly know how long it will take. However, “they” are often powerful and have the money we need, so we need to answer their question, even though we cannot."
It's a really long article, but well worth reading. You will find the full article here:
Estimation is Evil (PragPub)
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