We need to create some solution with a new technology, in which no member of my team has any experience.
The higher management demends the tentative dates of the working solution.
After a week of investigation, my team still can't give even a rough estimation of time. We made the list of possible problems, but all of them demands their own investigation. Furthermore, according my experience, I am sure, that we have only half of the future problems (in a best case) in this list. During implementation we will meet a lot of issues, that we can't predict today because of our current poor knowledge of the used technology.
Of course, I understand that the final date like “when it's done” is unacceptable for the higher management.
So, how should we estimate such non-estimability projects?
I understand that this question sounds a little bit stupid, but I'm sure, that all of us have this kind of problem (especially in the Software Development area).
Maybe we should:
Try to guess the time (make a guesstimation) and multiply it by two (just in case). Than pray that we can finish in this period.
Ask for more time for the investigation. But, of course, the higher management will not like this. And the whole time of the investigation will be unknown also.
Don't take this project at all, defer because we do not have enough knowledge in the demanded technology (not the best choice for image of our department).