> (In reply to Santiago Dueñas from comment #4)
> > In this case, the peak is from bug 27320.
> 
> > It was submitted on Feb 2011 (that's why it is shown at that point in the
> > chart) but its first action was made two years later (April 2013). Its
> > current priority is Immediate.
> 
> I think we have a problem of perspective. Your perspective seems to be
> data-centric: "how old were the bugs created at this point of time when they
> received their first action?" We actually care about our own perspective as
> bugtriagers (yes, we are so self-centered people)  :) : "how old are today
> the open bugs that haven't received any action yet"? And last month? And a
> year ago?
> 
> We want to see whether we are processing those bugs faster or slower than
> before, whether we succeed addressing more important bugs faster or not. In
> this sense, I wouldn't expect high peaks emerging, since the highest
> increase from month to month can only be 31 days (unless you reopen hundreds
> of very old bugs, an unlikely scenario that would reflect a legitimate
> higher peak).
> 
> Let's agree on these points before tying to solve anything else, please.

I've added some new charts that try to show this.

These new ones are in top of the page and are "Time opened by Priority (median)/(average)". Former "Time opened" charts are now "Time to close by Priodity (median)/(average). If you go down, you will see same charts but by Severity.

Let's focus on "Time opened by Priority (median)". It shows how old your opened bugs were at a certain point in time, in median.

If you select the first point with data, Aug 2004, it means that those bugs that remained open at the end of August were submitted (opened) in median around 15 days ago for most of the priorities. If you go to the next point, Sep 2004, it means the bugs that remain open (those from August that are not closed yet and those from September) were opened X days ago by priority, an so on.

These charts have some problems:

- A peak that goes down doesn't implies you are closing the oldest bugs. It can means that there are more bugs that were open recently, decreasing the median. You can see this behaviour in Feb 2011. The median of Unprioritized bugs is 530 days because there's only one bug that were opened 530 days ago. The next month, the median goes down to 282 days because another bug was opened in Mar 2011 and at the end of that month none of them were closed.

- High lines can hide or shadow your work on new bugs. If you are closing new bugs very fast and you also have old opened bugs, you won't see any change in the lines.

- Take into account that we are using the current priority of a bug. I think that for these kind of charts, it makes more sense to take the priority of the bug at that time, but it raises another problem: changes in lines might be produced by changes in the priority. If you change the priority of a bug, the old priority line will decrease while the new one will increase.

One possible solution to these problems is combine these with historgrams or distribution charts.