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problem combining burndown charts
Hi, I've come across a problem in RTC 101. I am running a project with a handful of scrums; each has their own development stream and that's working fine - I can look at burndown charts for them separately.
However, my management would like to see a single burndown across all five scrum teams, so I created one and added all five teams to it. The output wasn't what I'd expect - it seemed to sum everything to the correct total but then it drew the line straight back down to the x-axis.
I did some experimentation and a combined burndown for any two of the scrums seems fine. Add any other, and the same result happens - the line goes crashing back down to the x-axis. Great data for my manager but possibly not a real representation of the team's progress!
I'd appreciate any advice you may have here; is this a known problem? (I did cruise the forum but didn't go a long way back.)
Thanks
Ewan
However, my management would like to see a single burndown across all five scrum teams, so I created one and added all five teams to it. The output wasn't what I'd expect - it seemed to sum everything to the correct total but then it drew the line straight back down to the x-axis.
I did some experimentation and a combined burndown for any two of the scrums seems fine. Add any other, and the same result happens - the line goes crashing back down to the x-axis. Great data for my manager but possibly not a real representation of the team's progress!
I'd appreciate any advice you may have here; is this a known problem? (I did cruise the forum but didn't go a long way back.)
Thanks
Ewan
3 answers
I was able to reproduce the problem (obviously the burdown of our planning team area has the same issue since the planning developers tend to plan more than the rest of us). It is caused by javascript's handling of the long type. The problem seems to be caused by an overflow problem when the sum of the durations is big. I am trying to find a workaround for this. If there is a fix, it will be just a fix to the report template.
I guess I was too quick to blame this on javascript. The problem is in our backend and this will require a fix in the server code. Our database stores the duration value using milliseconds. Summing those up requires a long value. The BIRT oda driver does not support longs. So to get around the problem we had to convert the duration seconds, then did the sum and returned the sum as an int. A bug in the above code was casting the duration to an int, then made the conversion to seconds. That caused an overflow.
I created a work item to fix this in 2.0.
https://jazz.net/jazz/resource/itemName/com.ibm.team.workitem.WorkItem/74631
I created a work item to fix this in 2.0.
https://jazz.net/jazz/resource/itemName/com.ibm.team.workitem.WorkItem/74631