> It's impossible to predict the future, and it's impossible to predict the complexity of something you've never done before. Given that, estimates can not be useful, other than as a tool for political post hoc justification.
It is, however, possible to provide more information than "whatever" about how long it will take to achieve a goal. I have had goals I've worked on that were summarized with things like
- Could take anywhere between 2 days and 2 weeks, depending on factors
- Has an external dependency on X, and we don't have any insight into when X will be available
- May have other external dependencies, but we won't know until we're a few days into the work
- Not sure yet what the complexity of using <this API we need> is, so we'll need to check back in with more information once we have some time to experiment with it
- Expectation is about 5 days, on this, but it could be as short as 1.5, and could be as long as 3 weeks, depending on some factors
All of those things are more information than you had before, and allow the people that make decisions (which may be you and your team, or may be someone higher up the chain) to make _better_ decisions (or at least, better informed decisions)
And if you're working on something that you literally have no information on what's required for it, what the complexities might be, what the unknowns might be, etc... then perhaps the task you should be working on is "Identifying the work required to achieve <goal>", not "<goal>".
It is, however, possible to provide more information than "whatever" about how long it will take to achieve a goal. I have had goals I've worked on that were summarized with things like
- Could take anywhere between 2 days and 2 weeks, depending on factors
- Has an external dependency on X, and we don't have any insight into when X will be available
- May have other external dependencies, but we won't know until we're a few days into the work
- Not sure yet what the complexity of using <this API we need> is, so we'll need to check back in with more information once we have some time to experiment with it
- Expectation is about 5 days, on this, but it could be as short as 1.5, and could be as long as 3 weeks, depending on some factors
All of those things are more information than you had before, and allow the people that make decisions (which may be you and your team, or may be someone higher up the chain) to make _better_ decisions (or at least, better informed decisions)
And if you're working on something that you literally have no information on what's required for it, what the complexities might be, what the unknowns might be, etc... then perhaps the task you should be working on is "Identifying the work required to achieve <goal>", not "<goal>".