Hi @Sebastien_RATEL,
Unfortunately, with the default cycle time measures, it is not possible to build such a bubble chart. There is no dimension available that would allow grouping issues by their cycle length, like cyce intervals. Without it, eazyBI cannot aggregate the number of issues with the same cycle-day value to drive the bubble size.
We have this improvement on our backlog to provide interval dimension for issue cycles, and I have added your use case to it. I will update this community post once there is progress.
Meanwhile, you can calculate the cycle time using a JavaScript-calculated custom field and enable an interval dimension for that numeric value. This allows you to group issues by their cycle time intervals and use the issue count as the bubble size in the chart.
Please see this community post for guidance on setting up the JavaScript calculated field and interval dimension:
Best,
Zane / support@eazyBI.com