How to Deal with Not Reproducible Bugs???

As promised folks, come up with fresh article which every tester's face such situation across his career. I have tried enough efforts to highlight how to deal and what possible things you can try out to make it reproducible from not reproducible.

This kind of situation is nightmare for tester/QA community, specially when your application is live and customer is getting affected financially.As a Tester, i have come across of situations where some bugs won’t reproducible most of the times and i infer that many of the testers might have gone through the same situation multiple times across his/her testing career.Its tough to convince the developers from QA perspective for not reproducible bugs.When count of Not Reproducible getting increased, Chaos start from every end(Client,Third Party,Project Management Body,Top Management, Developer).Everyone is trying to prove that i'm not the culprit and QA is trying to find some support, most of the cases he won't get any.

Possible things you should try to reproduce the not reproducible.

1.Multiple post back via CTRL+F5 from browser - Check whether multiple request getting submitted or not. Ideally Duplicate request should not be submitted if you press CTRL+F5 from the page where you submitted the request already in on going session.

2.Due to caching of browser - Make sure you attempt clearing a browser cache. Might be caching data not allowing you to get the desired result.

3.Multiple insert on clicking button or link multiple times
4.Due to loose connectivity between DB and Server, Transaction is slow.Getting completed but not reflects to user.

5.Database table definition change i mean New Column introduced which is causing such behavior. Sometimes DB/Dev team has just altered the table definition or insert the new column or delete the new column but not communicated to QA and while testing with those changes showing some abrupt behavior.

6.Latest Store procedure/DB changes might throwing some non-sence :) 

7.Try entering the same data(Ditto) and enter the same record in the system.
Personal Observation : Same record getting displayed as success on screen but not getting reflected on the DB.

Demand/Things to do to reproduce the not reproducible:

1.First steps to deal with such bugs as QA is, Keep yourself Calm and have patience.Don't get frustrated even after the multiple attempts from your end with all possible things you can try.

2.Ask dev team whether proper logging mechanism is in place and specially the bug reported event getting logged into the application logs.

3.Ask for the exact or around time when issue has occurred and investigate along with DBA what DB activity has happend during that time.

4.Observe the things precisely and take a note of output on each stage of the transaction.

5.Try looking into your test results and check whether you reported such incident which is occurring in a rarest case.

6.Demand for exact sequence and Screenshot/Video for the instance occurred at client end(Politely or in a way he doesn't get offended :)).

7.Try to replicate the bugs in all available environment(Dev,QA,Staging/Pre Prod/live)and check whether you are getting the same result on all environment,If not get deeper into the environment where you get the different results.

8.Check the Hardware/Software details of the environment on which not reproducible been spotted.

9.If your customer is supportive, ask him/her to show case the exact sequence via remote to you.But this is something which you should try when you are running out all the options.

10.Make sure customer is following the guideline sent to them along with the software delivery i mean Min System config,Hardware/Software recommended or any other prerequisite.

11.Client running the software with all proper system configuration.