This tool is developed to help POs carry out macro sizing independently.
It allows you to estimate a workload in story points, and to transpose it into Man days based on a pool of questions. The more precise you are, the more precise the tools will be.
The tool does not have the intelligence of a human Scrum master/lead developer, it is only there for informational purposes, and does not commit the development teams in any way.
If you want to have a validated sizing, you need to refine topic with team properly.
Have fun with all this numbers !
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