Hi AlexK,
Generally the chart is created as follows:
1. Create one category data grouping with:
grouping expression: =Fields![RowIndex]
label expression: =Fields!Projectname
This will create a group for each row of the data source and label the group with the project name.
2. Create one values data grouping with:
Value Expression: =TOTALDAYS(Fields!Milestone2 - Fields!Milestone1)
This essenitally creates the chart attached to the post.
The problem is that the subtraction operator for date time variants in the current version is not defined.
This problem will be fixed in the upcomming service pack.
Best Regards,
Nevron Support Team