Someone asked me this question, and I have observed a similar thing in other teams before. In a (formerly) Waterfall-Oriented environment, a developer claimed, "We can't tell you how much effort this is until we have the Specification document!" It's the same question, just in different form.
Environmental influence
There are so many environmental factors in here that contribute to the statement being a problem which needs to be solved that I am tempted to write an entire book about it. Without digging any deeper, here are just a few factors which hint that the initial question is merely the symptom of a more severe problem:- Fear. For example, fearing the Unknown, fearing to not deliver, fearing to fail, fearing to disappoint - the stronger the fear element is, the more likely people will demand a reliable plan.
- Ambiguity intolerance. People or structures with low ambiguity tolerance prefer a bad plan, doing the wrong thing right over no plan and doing the right thing.
- Priority issues. If we're really working on the most important thing, the question isn't as much how long it takes as what is the best way forward.
- Alignment issues. An organization which expects teams to create reliable plans upfront, shouldn't be confronting developer teams with completely unknown topics just a few days before visible results are expected.
- Slicing issues. There are always opportunities to deliver something based on an upfront plan and show some form of result, although the total amount of work required to get the expected final result doesn't decrease by putting more effort into creating thin slices.
- Scoping issues. An Epic that takes more than an Iteration can't be planned down to a Sprint. The best thing we can do is deliver a portion of the work.
- Push process. When stakeholders push work into the team and expect a specific result in a fixed time, we end up with the typical "Iron Triangle problem": Fixed time, fixed budget, fixed scope. What's left is a compromise on quality.
It should be the responsibility of management, ScrumMasters and coaches alike to create an organization where these issues aren't so relevant.
All that said, there's always the chance that something happened and we need a kind of solution quickly. In the first step, it's important to understand which of the above environmental constraints we have, and how strong or weak these are in relation to the team's work.
For example, if the fear factor is high on team side, we need to approach planning and delivery different from how we would if the main issue is unfamiliarity with slicing.
In my next article, I will explore some techniques in complete disregard of these external constraints that can help a team confronted with planning a completely unknown topic.