How often do you find a really serious bug the first thing you do on monday mornings? Or any mornings for that matter, when you just started to look at it.
How often is it the other way around, that the first thing you do is trying to remember what you did on friday, to cause that serious issue you found at 4.30 before you were leaving for home and for the weekend?
For me, it is always the latter. Not only fridays, but any day of the week, the most common time when I find bugs is really late in the afternoon, preferably if you are having an appointment or anything right after work. =) But why is that?
I have three possible explanations, that I have been thinking about:
1. You could be testing a really hard-to-set-up system, that takes half of the day setting up before it is possible to test even a little bit. This is the reason for me every now and then. Recently we have been setting up load tests during night, which have failed a couple of times, so the mornings have been devoted to investigate logs for failure explanations and then it has taken some time to reset databases and getting up and running again. Usually with a bug fix or configuration tweak that also takes some time to verify.
2. Exploring the product and its features and areas all day has made you get more sensitive to finding the weaknesses, and poking the system in these spots make the really tricky bugs appear. These might be the most severe afternoon bugs, or the opposite, the ones that are too complex to be a threat to the product and just are hard to fix, with no value added if fixed.
3. You are unintentionally defocusing from the tasks at hand since it is getting late in the day and the lack of energy is carrying your senses in completely other directions from what you have been doing all day. The defocusing strategy is actually something that is brought up in rapid testing contexes for finding other types of bugs than you normally do. Lack of energy just makes you get in this mode automatically during afternoons. These bugs are more too often hard to recreate for investigation, since your lack of energy might miss out on observing the reason behind the bug.
Have you experienced the afternoon bug heuristic? What have been causing you to find them? and specifically, why do you find them at that time?