Debunking the statement 'estimates never work'


In the post Black and White #NoEstimates stance considered harmful, I mentioned many taking part in the discussion from both sides agree the debate around #NoEstimates is often unproductive. In the post, we looked into what kind of interactions feed the fire and saw an example of a message created to provoke, claiming estimates never work.

In this post, we will see two cases where the same proponent says estimates do work, showing the repeated false claims to the contrary are intentional. In addition, we will discuss the logical fallacy these statements are based on and with one example showing how they are false.

Then before we close, we will shortly discuss why some of the key #NoEstimates proponents knowingly repeat false claims that 'estimates never work.'

Where do the claim 'estimates never work' come from?

When looking for answers to why so many in the software development community are making this claim, I came across Vasco Duarte, author of the #NoEstimates book. Vasco released the book in 2016 and is highly active on Twitter under the #NoEstimates hashtag. Nearly every day, Vasco posts multiple tweets under the #NoEstimates hashtag. He intends to grab attention, dismissing the value of estimates and the people who use them. Seeing the following tweet, I decided to understand if he thought estimates never actually do work. So I asked him the following question to know where he stood on the topic:

I thought Vasco's answer below was quite positive because he accepts it's valuable to have a tool '..allowing teams to make decisions about options that come up during backlog discussions'. Because he says with a "..simple slicing heuristic.." you can achieve this value. Thereby accepting the value of the premise. To confirm this, I followed up and asked:

His response:

#NoEstimates author in contradiction - Value in Estimates or Not?

By looking at Vasco's tweets above and the repeated tweets with the same message, Vasco completely dismisses the value of estimates. Yet in his book, chapter 5, '1-2-3: Step by step towards # NoEstimates', under the heading ' Move to story points' he says that:

Story Point-based estimation gives a better understanding of how things like risk, complexity, expected dependencies for each Story, etc. Given that a large amount of time it takes to deliver one Story is spent waiting, Story Point estimation is more likely to help you assess the true impact of one Story in your project."

So Vasco clearly understands there is value in estimates, yet consistently contradicts this every time he claims estimates:

  1. are helpful only for "..blaming, pressuring others, etc.."
  2. do not work "for containing costs or hitting a deadline"

This doesn't make sense, or does it? Let's touch on this question before we close. But let's first debunk Vasco's false statement many have been led to believe that: 'estimates never work.'

Debunking 'estimates never work'

Vasco and others repeating these claims don't realize they are logical fallacies. In the examples above, Vasco makes a faulty generalization. Here is the example from Wikipedia and the #NoEstimates fallacy side by side:

If one sees only white swans, one may suspect that all swans are white.
If one only sees estimates used with bad intentions, one may suspect all estimates are used with bad intentions. 

To debunk the statement' estimates never work,' we only need a single case, one example, where an estimate is used successfully to show statements making this claim are false. Let's extend the story from the #NoEstimates book, and let's introduce Carmen, the main character in the book, to the following case:

Case Example: Carmen and her team identify a better solution using estimates

Through discussion with users and stakeholders, Carmen identifies a problem the team needs to tackle. During a sprint planning discussion, it becomes clear there are different options available.

During the initial discussions Carmen had, a solution idea was identified that stakeholders thought made sense to go ahead with. Later during planning, the development team's discussed the problem and the proposed solution, solution A. The team estimated the work might be around 13 story points. They expected it would take a bit more than one sprint to complete. The reason was that there were some known unknowns and unknown unknowns, as always. Given their information, history, and velocity, Carmen and the team knew it would likely take 1-2 sprints to complete.

During the meeting, the team identified a different approach. Let's call it solution B. Estimating solution B; the team expects it to be around eight-story points yet provide the same value. Given their velocity, the story will likely be completed within one sprint. This is because there were no 'known unknowns' about solution B, so the team is more confident about this estimate. In other words, they expect the estimate for solution B will have less deviation than the estimate for solution A.

Based on these findings, Carmen and the team agree to implement solution B. In addition, Carmen will validate their thinking and present a quick mockup of the proposed solution to users and stakeholders who participated in the initial discussion. To ensure they didn't miss anything during the team discussion and validate the solution delivers the value they are after.

By making this single case, based on real examples, we can see the claim that "estimates never work" is false. Cases such as these have repeatedly come up during my 20+ year career as a Software Developer, Scrum Master, and Product Owner. I am not the only one, as teams worldwide are using estimates successfully in their work.

This raises the question, why on earth are some of the key #NoEstimates proponents knowingly repeating false claims that 'estimates never work'?

#NoEstimates proponents knowingly making false claims

Now, this is an interesting question. In one part, it has to do with spreading the #NoEstimates idea, selling books, and related consultancy services. Another factor has a darker side, as many are trapped into believing the false claims and take up the harmful and aggressive black and white stance on estimates wasting a lot of time in unproductive arguments and causing polarization in our community.

What's next?

In the next post, I will dive deeper into the purpose of repeating these false claims, keeping the polarization in our community rampant. The post, Did you get caught in the #NoEstimates trap?, shares an inconvenient truth about the methods we see used.

About Smart Guess We help teams educate stakeholders by providing actionable answers to common misconceptions about estimates. So more teams can use estimates to their advantage, and fewer are held accountable for delivering on impossible deadlines.

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