Tuesday, December 5, 2017

Take every bug report seriously (Part 2)

Introduction


Many engineers value rationality above reality. Even if they see something is happening in front of their eyes, they will want to discard it as a "one-off" case if they can't find a reason behind this. 

I have seen this during several instances. Many a times, bugs filed by QA Engineers are discarded by Dev Engineers as "Not Reproducible" if they cannot find a reason why the bug would have happened in the first place; or if they cannot reproduce it on their systems ("It works on my machine!").

In this series of blog posts, I will post many stories that helps us (the engineers) understand the importance of treating every defect seriously.

Story #1


Story #2

Eight years ago I was working as an escalation tech for a high end computer manufacturer that is no longer in business. They specialized in very expensive home rigs. One of my techs received a call from a user on the east coast complaining that their computer would reboot for no good reason every evening around the same time, give or take a couple hours. The tech checked all the obvious settings (BIOS, Power Management, etc.) but could find nothing that was telling the computer to reboot at any particular time. It was running <shudder> Win95, not NT so there were no OS timeouts available. 

They then started working the hardware angle -> remove all add-ons and see if it still has the same problem. Disconnected the printer, scanner and joystick and ended the call. A couple hours later user calls back saying the computer had just rebooted on its own again. The new tech followed up with the first tech to see what else needed doing and they ended up escalating to the supervisor for an RMA of the power supply or mobo. Sup decided to RMA both because he could not prove which one was bad.

Customer got new parts, installed them himself and was up and running for the entire weekend. Monday rolls around and he calls back in the late evening (7 or 8PM) with the same problem. This call got escalated straight to the sup who decided we needed to RMA the entire tower and have the repair team take it apart. A week later customer gets his system back with all new components inside. The only thing that was not replaced was the case (serial number). They even replaced the front bezel of the case in case it was a malfunctioning reset switch.

That night he calls in again WITH THE SAME PROBLEM. At this point, my sup decides there is no way the problem exists within the confines of that computer case so he hands it to me to try and figure out (he didn't like me very much). While I'm talking to the customer (about 50 minutes into the call) I hear a noise in the background. He immediately lets me know that the computer has just rebooted. The noise that I heard did not sound anything like what you would expect to hear from a computer that just came out of the box, so I asked him what was the noise that I had just heard. He informs me that his wife had just come home from work and was "finishing her business in the bathroom".

I pondered this new bit of information for a while. I asked if she works a regular 8-5 type job and always comes home at the same time, every weeknight. His response was that sometimes she works late and then gets to come home early the next day, but that it never varies by a couple hours.

After the computer was back up in Windows I asked him to go flush the toilet and then come back and check the computer. He did and sure enough, it was in the process of restarting. I then asked him to check for any wires leading into the tank of the toilet. He informs me that there is no tank on his toilet. He "only buys the best" so instead of having a tank, he has a water pump that pumps water into the toilet from a water reservoir in the basement that is kept at room temp (also supplies water for the bathroom sink and indoor watering system for all their potted plants - more money than he knows what to do with, obviously).

The water pump just happened to be on the same circuit as the outlet that his computer was plugged into. Despite the use of a surge protector, the water pump kicking on put enough of a drain on the circuit to cause the computer's power supply to momentarily die (this was 8 years ago, before digital power supplies), but was not a surge so the surge protector never tripped. I had him move his computer desk to another wall in the same room and plug into one of it's outlets instead. This moved him to a different circuit and solved the problem.




[NOTE: This popular story has been taken from Internet. I do not know the very original author, so have not attributed to him/her.]

Take every bug report seriously (Part 1)


Introduction


Many engineers value rationality above reality. Even if they see something is happening in front of their eyes, they will want to discard it as a "one-off" case if they can't find a reason behind this. 

I have seen this during several instances. Many a times, bugs filed by QA Engineers are discarded by Dev Engineers as "Not Reproducible" if they cannot find a reason why the bug would have happened in the first place; or if they cannot reproduce it on their systems ("It works on my machine!").

In this series of blog posts, I will post many stories that helps us (the engineers) understand the importance of treating every defect seriously.

Story#1


A complaint was received by the Pontiac Division of General Motors: 
"This is the second time I have written you, and I don't blame you for not answering me, because I kind of sounded crazy, but it is a fact that we have a tradition in our family of ice cream for dessert after dinner each night. But the kind of ice cream varies so, every night, after we've eaten, the whole family votes on which kind of ice cream we should have and I drive down to the store to get it. It's also a fact that I recently purchased a new Pontiac and since then my trips to the store have created a problem. You see, every time I buy vanilla ice cream, when I start back from the store my car won't start. If I get any other kind of ice cream, the car starts just fine. I want you to know I'm serious about this question, no matter how silly it sounds: 'What is there about a Pontiac that makes it not start when I get vanilla ice cream, and easy to start whenever I get any other kind?'"

The Pontiac President was understandably skeptical about the letter, but sent an engineer to check it out anyway. The latter was surprised to be greeted by a successful, obviously well-educated man in a fine neighborhood. He had arranged to meet the man just after dinner time, so the two hopped into the car and drove to the ice cream store. It was vanilla ice cream that night and, sure enough, after they came back to the car, it wouldn't start.

The engineer returned for three more nights. The first night, the man got chocolate. The car started. The second night, he got strawberry. The car started. The third night he ordered vanilla. The car failed to start.

Now the engineer, being a logical man, refused to believe that this man's car was allergic to vanilla ice cream. He arranged, therefore, to continue his visits for as long as it took to solve the problem. And toward this end he began to take notes: he jotted down all sorts of data, time of day, type of gas used, time to drive back and forth, etc.

In a short time, he had a clue: the man took less time to buy vanilla than any other flavor. Why? The answer was in the layout of the store. Vanilla, being the most popular flavor, was in a separate case at the front of the store for quick pickup. All the other flavors were kept in the back of the store at a different counter where it took considerably longer to find the flavor and get checked out.

Now the question for the engineer was why the car wouldn't start when it took less time. Once time--not the vanilla ice cream--became the problem the engineer quickly came up with the answer: vapor lock. It was happening every night, but the extra time taken to get the other flavors allowed the engine to cool down sufficiently to start. When the man got vanilla, the engine was still too hot for the vapor lock to dissipate.


[NOTE: This popular story has been taken from Internet. I do not know the very original author, so have not attributed to him/her.]