When using trend charts, the historical values of fields matter. However, when users reorganize their project, the data integrity is broken. The historical values of the fields should be recalculated to get correct trend charts. This doesn't happen by default.
The only option is to contact the administrator who can only do a recalculation per field on the entire issue db. This is an intensive server job and can't be executed during regular work hours because of it. It's a shame because we only need to recompute the history of a couple of fields on one particular issue at a time.
Examples of such restructuring that happen regularly is moving items to new parents:
Moving documents to another project
Adding test objectives as siblings to a parent test objective.
Metrics we follow up on trend charts include:
Defined Count (number of requirements, test cases, ...)
(Total) Planned Count (number of test cases that are to be run)
(Total) Run Count (number of test cases run)
(Total) Pass Count (number of test cases with a pass)
Suggested improvement: It should be possible to recompute the history of an item.
Recompute history of items in the chart/report query before running a trend chart or a historical view/report (probably not best solution due to performance).
Add a Recompute History feature on the edit window of an item.
Add a Recompute History button on a trend chart (or as a right click menu feature).
Recompute history of an item when saving (not good for performance)
Add a scheduled job to recompute the history over the entire db as part of the weekly calculations. (only good to keep data integrity, but not a good solution to answer the ad hoc need for charts)