Saturday, January 10, 2009

It is snowing (:) decisions

During the last week it snowed in the Netherlands. While most of the roads are covered with snow I had to go to my work. I already knew that this will be a task which involves some risks because the weather news already warned me for this situation.

Normally there are several roads to take to get from my home to my working place. The decision to choose one of the options is based on available traffic on those roads, current traffic jams and possible chance on traffic jams. These possibilities are also based on the moment in time and the possible delays those options will give.

In this situation I had to calculate also the possibility those roads are cleaned from snow. In those days I had to choose for the main road as the risks for incidents would be much smaller. Alternative roads were no acceptable option in this case.

This is similar for system development. Under certain conditions it is better to use only main functionalities to get from the start of the system to the end of the system. Alternative scenarios should be avoided. For testing this implies only test those situations which can be defined as intended usage.

Before I stepped in my car and drove away I had to do some preparations. First make my windows snow-free. I also noticed that the street I'm living in was not cleaned. There were some decisions I made before I started the journey to go to work.
1. Do I have to go to work at that moment and take some risks?
2. Am I able to drive?
3. Which risks are there in the area I can oversee?
4. What actions can I do?

ad1: Yes, there was a production release scheduled and there were still some tests open which might be performed so production release could continue
ad2: Yes, I have a driving license, only no winter tires under my car and I could turn the car's engine on
ad3: there is snow on my car; if it can be removed I would have clear vision. There was snow in the street; if I was able to cross that area and managed to reach the street with lesser/no snow I minimized the risk for accidents. There were cars standing in my street which might by possible targets to hit due to bad weather circumstances; If I hit those the journey would be stopped or delayed based on damage.
ad4: I had to: turn on my cars engine, remove the snow from my car, drive safely to avoid the nearby objects, reached the first situation of go/no go (the snow free street)

You can compare these actions with an intake test; am I able to start testing and reach the defined goal.
At this moment I made important decisions to start driving using the main roads and defined a go/no go moment.

As I managed to reach the moment on which I decided to continue I knew that I had to calculate delay. As under normal situation I would reach a velocity of average 70 km/hour I noticed after using 1/5th of the main roads my average velocity was just 32 km/hour.

Gaining this information I introduced a new go/no-go moment. I asked myself if it was still possible to make the production release available although I will have a delay? Will I have enough time left to finish testing as due to the delay the testing window minimized? Will others who's support I need for testing, be available because the made the same decision to go to work?
Is it all worth to get there because I also have to go back at the end of the day? Can I speed up to increase my average velocity? Is there other information about traffic jam, weather conditions and road conditions available?

I first started with gaining information; I listen to the radio, checked the internet for traffic jams and called a colleague which would be heading the same direction.

At that moment I accepted the risks that no people and no were available. I didn't choose to speed up as the chance to be involved in an accident will be larger due to weather and road conditions in combination with the tool I have: a car without winter tires.

In terms of software testing you can translate this to the possibility to reach the goal within minimized time and clarifying risks for that moment and making those risks acceptable.

After I made that decision I watched more carefully I kept to the defined travel schedule. I acted on every situation. If I felt my car was slipping a bit I decreased the speed. If there were better conditions on the road I choose to drive the left lane instead of the right lane. You have to know that driving the right lane is introducing additional risks as most of the cars are driving on the left side of the road and the level of snow is lesser then on the right side. I accepted that risk. Knowing that the chance for accidents is lesser when keep paying attention and using controlled speed level. Also knowing that when something happens help would be available fast enough to be able to reach my goal at work.

Almost reaching my work I came in an area were the roads were not cleaned yet. I suddenly realized that I already crossed the point of no return. I started listening more carefully to the car, focused more on the road and the conditions and lowered my speed to almost 10 km/hour knowing that this will reduce the average velocity. I also paid more attention to the circumstances as the weather forecast for the following days would be similar and I had to reproduce the steps I had taken to reach my goal.

Finally I was sitting behind my desk and realized I performed a test process during those exiting hours. In this case the process was not covering all circumstances. As I only used one road to get to work. I didn't monitor the outcome of the other roads I could have taken to get to work. What I did was:
1. Identifying the goal: go from A to B;
2. Indentifying the need: release to production;
3. Identifying the risks and defined the first go/no-go moment: continue based on intended usage;
4. Monitor the chosen route and acting on changing circumstances: Am I still acting on intended usage;
5. Defined another go/no-go moment: am I able to reach my goal based on other conditions;
6. Cross the point of no return and remember the actions to make the defined route reproducible.

The final outcome was a proven and defined route which made me able to use my environment (roads) to obtain my goal: get from A to B. I think this can also be done in software testing: You don't have to cover everything. You don't even want to know what kind of coverage you have. If you are able to use the system based on intended usage and you accept the risks that you didn't test everything you only have to make sure that users are using the system based on the intended usage. Tell them what they are allowed to do and what they shouldn't use. And in case users are not listening make sure that there is a quick action force available to recover damage. Is this a nice way of testing? It depends based on the circumstances you are into. At least a Goal Driven Testing approach might work for you.

1 comment:

  1. Nowadays I cycle to work, but I recognise the decisions you had to make when I had to travel a lot by car. I just have never made a link with testing!