People are used to making plans and taking decisions using estimates, even though they are often not so good in estimation says Gil Zilberfeld. The #NoEstimates movement explores alternatives for estimation. At the Agile Testing Days 2015 Zilberfeld will do a workshop on Planning with #NoEstimates.
The Agile Testing Days will be held from November 9-12, 2015, in Potsdam Germany. The motto for the 7th edition of this conference is:
Embracing Agile for a Competitive Edge - Establish leadership by delivering early, rapid & iterative application releases
InfoQ will be covering this conference with write-ups, Q&As and articles.
InfoQ interviewed Zilberfeld about why people do estimation and how they look for ways to get better in it, and had a discussion with him about alternatives for estimation.
InfoQ: Can you briefly explain what you mean by "Planning with #NoEstimates"?
Zilberfeld: We’re so used to base our planning on cost estimates. It’s so ingrained in us. When you have an idea, or a solution, the gut reaction of management is to ask "how long will it take" or "how much will it cost". And then we decide to do it based on the answer.
That’s a shame, because we humans are really bad at estimating. We should make decisions based on better methods, and there are alternatives. The workshop is based on alternatives to estimates, that you can find around the discussion around the #NoEstimates hashtag.
InfoQ: Why do people do estimation, what do they expect from estimates?
Zilberfeld: It’s very interesting. If you ask people, they will tell you that without an estimates they can’t make a decision about a project.It’s like they are stuck until you give them a number. The thing is that we don’t really *need* it to make the decision, but we *want* it. We want to make confident decisions, and when we get the number we try to see if it fits our experience, point of view, ideas and knowledge. If it fits somehow, we can make a "go" decision with confidence.
The other part is feeling in control. The estimate is like a fog vacuum - it clears all the uncertainty away. If that number fits with our views, it gives us confidence we can ride the tiger - control the project - when things go wrong. All it takes is the right number :)
InfoQ: It appears to me that most people are not good in estimation. Are there ways to get better in it?
Zilberfeld: Sure you can get better at estimation. The problem is that as good as you get, reality will bite you. There’s a big disconnect between how we think things will go and what will actually happen. We’re optimistic, we think we can control the tiger, and our view skews our numbers.
Hofstadter’s Law says: It will always take longer, even if you take into account Hofstadter’s Law. We play a game in the workshop that gives all the conditions to get estimations right and almost all people get them wrong.
We should remember that we use estimates to make decisions. That’s only one way, and if we are not good at it, maybe we should try other methods.
InfoQ: If estimation is not the way to go, what’s the alternative that you suggest?
Zilberfeld: We can look at the team’s track record - if they did something similar in the past, chances are you don’t need the estimate, but use the old actual cost. If however, the team never did this before (or what if no one did this before?), there’s not much point in asking for a number. What good will it do? Instead of making a go/no go decision around a 2 year cost estimate, we can budget small experiments that will tell us if we’re on the way to achieve the grand goal. We change the way we’re planning, from big up-front plan, to deliberate discovery using cheap experiments, which we can stop any time.
Finally, if we’re so keen on estimating, why not estimate business value, rather than cost? These are still estimates, we can prioritize projects based on value, rather just by their cost. When leaving out business value, we make really bad decisions.
InfoQ: Does #NoEstimates mean that you should never ever do any estimates? Are estimates evil?
Zilberfeld: #NoEstimates sounds like it’s about abolishing estimates. But it’s really about searching for alternatives. The question comes up frequently, but the answer is the same from all the #NoEstimates proponents - if asked for an estimate, give an estimate. Estimates are not evil, but they are very much abused. They are often thought of as promises rather than guesses. So when the estimator misses, there’s disappointment and sometimes anger. And maybe worse, when the estimator succeeds, his expert authority goes up, discarding any uncertainty that was in the process.
But that’s not all. Since people miss estimates all the time, we see managers "extending" estimates given to them. If I say something will take 3 weeks, my manager will try to buffer it saying it will take 5 weeks, and her manager will make sure we don’t miss by saying it will take 8 weeks. So a short project becomes a medium one, with all the committed resources for two months. As with the Student Syndrome, work expands to the time allotted, and that’s quite a waste.
Finally, if estimate don’t provide us with the tools we need, the whole planning process becomes wasteful. And if cost estimates are the only decision making tool we have, we’re going the way of the gut-feel, rather than the data-driven road. When you understand what you really get from estimates, it really doesn’t make sense using them exclusively anymore.
InfoQ: If people want to learn more about planning with #NoEstimates, are there some resources that you can recommend?
Zilberfeld: Apart from my workshop, you mean? If you want to learn more about #NoEstimates follow Woody Zuill, Neil Killick and Vasco Duarte on Twitter and join the conversation. Vasco also has a new book called, surprisingly enough "No Estimates". More and more people are now contributing stories how they manage with alternatives for estimations, and maybe you can pick an idea to try with your team!