Why is the cycle time changing when I query a past month

[Deleted user]

I run a cycle time report at the end of every month for one of my teams. I have 4 categories: To Do (open), In Progress (in progress), Ready for Release (resolved), and Closed (closed).  I go into the control chart and set the time frame to the 1st of the month to the last day (30th or 31st). I will choose one column at a time to get the cycle time for that particular status.... so for example, for April 2017's numbers, I would set the date range to 4/1/17 - 4/30/17. Then I only leave one column checked in the drop down.  So if I only choose "To Do" it will show me the average cycle time of any JIRA that entered and exited the open status during the month of April.

I did this for April on May 3rd 2017. The chart indicated the average time spent in "To Do" was 9w 2d.  However, I went in and ran the exact same report again, from 4/1/17 to  4/30/17 today (7/7/17) and the cycle time for "To Do" is 1w 1h 41m. How is this possible?  How does the data in a PAST month change? If I ran the report on 5/1/17, to me nothing would be able to change going forward since we cant go back in time.

[somethingblue]

Hi Jessica,

Is it possible that one of the issues was worked on again?  If an issue is reopened, worked on, and completed again, then the time for this extra work is added to the cycle time.  That could be why you're seeing this. 

Depending on how many issues there are you may want to see if the issue histories provide any clues as to whether or not issues may have been modified that affect this report.

Cheers,

Branden