Imagine if Stack Overflow had a guideline: instead of asking one question, you come and ask, in the same question, whatever comes into your mind, all your issues you had for the last two weeks. What would upvote and downvote mean? What would be the titles of the questions? How to accept the best answer? How to tag the question?
Bug tracking system is done to... track bugs. Tracking a bug means:
Creating a record saying that a bug might exist, with information about how to reproduce it,
Confirming that indeed, the bug exists and is a bug, not something by design,
Asserting that the bug is now solved,
Confirming that the bug was solved.
In a very simplistic model, 1 and 4 will be done by the customer, and 2 and 3 – by the developer.
Imagine the following log:
Day 1 [Customer] When pressing on “Remove” button in “Product details” window, the application hangs. Restarting the application shows that the product wasn't removed. The expected behavior is to remove the product.
Day 4 [Developer] <Issue reproduced>
Day 5 [Developer] <Issue solved in revision 5031>
Day 12 [Customer] <Ticket closed: issue solved>
The log is simple and clear. You can easily track what was done and when, which revision solved which bug, etc. For example, if the bug tracking system is integrated with the version control, when you view a specific revision, you can check what bugs were solved in it.
It's easy to find information. It's easy to see its state (is it reproduced? If the ticket was closed, why?). It's easy to filter tickets (I want to display tickets which concern only the UI of the plugins, given that I want only tickets which are open, older than one week and assigned to me by our interaction designer and are medium or high priority).
It's easy to reassign a ticket or to originally determine which is the person who should be in charge of the bug.
Now imagine the following log:
Day 1 [Customer] The app hangs when I press “Remove” button in “Product details” window. Also, the background color of the left panel is dark blue, while it should be purple. I also noted that the text of the “Product details” window is not translated well to German; is it expected? When the final translation would be available? BTW, have you received the new icon I sent for the “Publish product” action? I don't see it in the “Sync data” window.
Day 6 [Developer] I changed the color to purple.
Day 7 [Developer] Yes, it's normal that the translation to German is incomplete.
Day 8 [Customer] Ok for German. What about Italian? Lucia sent you the XML file two days ago.
Day 9 [Developer] It's ok now.
Day 10 [Customer] Ok for the “Remove” button? Strange, at my computer, it still hangs.
Day 11 [Developer] No, I wanted to say it's ok for Italian translation.
Day 12 [Customer] I see. Thank you. But there is a problem with the color. You changed it to dark purple, but it should be light purple, like the top panel on the main window.
Day 13 [Developer] I updated the icon.
Day 14 [Customer] The icon? What icon?
Day 15 [Developer] The icon you asked me to update.
Day 16 [Customer] I never asked you to update any icon.
Day 17 [Developer] Of course you asked. See this ticket. You wrote that the publish product icon should be updated. I've done it.
⁞
Day 100 [Customer] So, what about the entries in the log?
Day 101 [Developer] I have no idea what you're talking about. It's not even in this ticket, but in 6199. I'm closing this one as solved. <Ticket closed: issue solved>
Day 102 [Customer] Sorry to reopen it, but the problem is not solved. I'm talking about the entries in the log: I told you last week that the text is sometimes invalid when it contains unicode characters. Do you remember? <Ticket reopened>
Day 103 [Developer] I vaguely remember something like that, but after searching the last three pages of this ticket, I can't find any trace. Can you write again what was the problem?
⁞
Day 460 [Developer] I spent two hours searching for a trace of what you've said about the files sent encrypted through the network. I'm not sure I can find the precise request.
Day 460 [Customer] You guys should really be more organized. I notified you four times about this issue for the last two weeks. Why are you forgetting everything?
⁞
What's this log about? It was solved 43 times and reopened 43 times. Does it mean that the developer is so stupid that he can't solve the same issue for 460 days? Ah, no, wait, this ticket was assigned to 11 developers meanwhile. What's the deal? How to search for a specific issue? It's actually assigned to Vanessa, but her five colleagues are concerned as well by seven of the eleven issues in this ticket. When the ticket should be closed? Is it when half of the issues are solved? Or maybe ten out of eleven?
Note: You may believe that such logs don't exist. Believe me, I've seen ones more than one time.