Is there a SIMPLE way to create a report that shows the number of resolved task ?

[Viktar Kamiahin]

And groupped by project & users ? I want to see how many time (or percentage) each user spend by project ? 

[Jobin Kuruvilla [Adaptavist]]

Create a filter for the resolved tasks (resolution IS NOT EMPTY and other_criteria_you_want) and then use a pie chart or 2 dimensional statistics gadget to group them by project, user or both.

[Viktar Kamiahin]

You mean pie chart in dashboard ? 

[Nic Brough -Adaptavist-]

Yes, a pie chart is a good simple reporting tool

I'm more fond of the 2 dimensional statistics - can tell you more, but it's not as pretty.

[Jobin Kuruvilla [Adaptavist]]

Same here @Nic Brough -Adaptavist-. The 2D statistics is really valuable at times. You might dismiss it as too simple, until you start using it.