Introduction to Software Testing Management

Software testing management is one of the most difficult tasks out there. There are many reasons for this. First, a software product is not a tangible thing that can be measured, physically felt, or sampled. So it is difficult to test a software product. Second, software testing is still not considered a recognized trade and so finding professionally qualified people for the testing job is difficult. Third, unlike well-defined and standardized processes for product design, product development, quality control, and so on, which exist for any product development activity, similar standardized processes have yet to be defined for software testing. Fourth, tools for automation of software testing activities are still in their nascent stage, and it will take time to have sophisticated automation tools available for software testing activities. Fifth, effort estimation techniques for software testing activities are still being evolved, and currently effort estimation is done mostly on an ad hoc basis.

Yet, the importance of software testing is so immense! Any failure of the software product or application can cause damages to the tune of millions of dollars for any company. Even if the software defect is not so big, the support cost can run in the thousands of dollars over the life of the software product.

To better understand software testing management, let us first try to understand what is a defect in a product, how it affects a user, what the user feels when he finds a defect in a product after buying and using it, how to prevent defects, and finally how to identify and remove defects in the physical world. Then from there we can go to software engineering and software testing. From there we can move on to software testing management aspects.

Product Defect: A Case Study

Just the other day I bought a semi-automatic washing machine. It had a 2-year warranty on it, and the deal looked fine. So I bought it. My wife started using it, and everything looked fine till one day. That day my wife phoned me saying the washing machine is not working. I was in the midst of an office meeting. I was deeply involved in my task at hand and I got disturbed. Now my wife is very blunt when it comes to talking on the phone and when she says something to me, it is a command and not a request. I must do something immediately or else I face the risk of being called an incompetent person. Even if I am busy with something important, I must obey. Cursing my wife and the washing machine company, I told my wife to find the customer service phone number of the washing machine company from the product brochure that came with the washing machine and get it fixed. I also told my wife not to disturb me, as she can handle these things herself. When I came back home that day, I learned that the mechanic had found something stuck in the drainage system of the washing machine and the mechanic cleaned and fixed it. A few days later, my wife phoned me, saying that the washing machine again has some problem. I told my wife not to bother me, as she has the customer service phone number of the washing machine company and she can phone them directly. So my wife phoned the washing machine company and got the machine fixed. This happened many times over the next few months. Finally I decided to confront the service engineer myself and tried to get an explanation as to why it was happening. I found out that that particular brand of washing machine had a design problem and this problem was happening with most of the washing machines of that brand. I talked to customer service and explained my problem. Even after a lot of heated exchanges I was not able to find a solution from the company. Then I thought I should look inside the washing machine and find out the problem myself. So here I was disassembling the washing machine and trying to find out the root cause of the problem. I found out that there was a valve (to stop or start draining of water from the washing machine) connected to the drainage system of the machine and the valve used to activate when a lever attached to the machine was pushed. Dirt coming out of the clothes was getting deposited at the valve and clogging it. So the valve was not closing properly and water was getting drained even when the valve was in the closed position. Water should not come out when clothes are being washed. When washing is complete, you can open the valve to let the dirty water out of the washing machine by pressing the valve lever. I cleaned the valve and then tested it by filling water in the washing machine. I inspected the valve and the lever to find out the problem. I found out that even when the valve was clean the lever was not properly closing the valve and so the valve was getting only half closed. This was the root cause of the problem. I also found out that there was no option to adjust the lever so that it should be able to close the valve completely when operated. So far I was able to trace the root cause of the problem. Now I had to fix it. After thinking much, I decided to bend a part of the lever so that the length of the lever would get changed and so it can push the valve more and close it more. After some trial and error I was able to make the lever pull the valve perfectly. So the valve was getting opened properly now, but still the valve was not getting closed properly. To this day this problem could not be fixed even after many attempts by service engineers.

Case Analysis

What is the moral of the story? A small defect in a part of a product can dent confidence of the customers. I for sure will never buy any products from the manufacturer who manufactured that godforsaken washing machine.

This shows the importance of preventing defects in the first place and, if any defect occurs, finding it at the manufacturing site itself and removing that defect so that the defect is not passed to end users or customers.

Preventing as many defects as possible in the product and then trapping defects if any occur at the manufacturing site itself is very important. Right from product conception to product design to production, a process should be followed which will ensure that the product is as close to defect-free as possible. This means that when a machine prototype is passed to the machine design team, the machine prototyping team should ensure that no defects are introduced in the prototyping. When machines made from this design are then installed at the shop floor, the factory should ensure that no defects are passed to the product being made on this machine due to faulty material handling or bad machine design. These measures will ensure defect-free products through a thorough implementation of quality assurance processes. Similarly the product that will be produced using this machine should also go through the same quality assurance process at each stage of product conception to product design to product production. And at each stage in the manufacturing process the quality testing department should ensure that any defects which may occur in the product are trapped and faulty products are either reworked or rejected.

In the physical world preventing and removing defects is very much possible to the extent of having products 99.99999% defect-free. It is possible because a number of factors that cause defects can be determined and then removed from design or during the manufacturing process. Nowadays product development has matured so much that in most of the industries defects due to faulty conception and design are nonexistent. They have also mastered manufacturing processes so that they can achieve defect-free products to the tune of 99.99999%. They have feverishly implemented six sigma programs, ISO standards, lean manufacturing principles, quality circle programs, and so on. So the first principle is that defects should not be introduced in the products. The second principle is that if some defects enter at any stage, then they should be trapped before the product enters into the next stage in the production cycle. One good example of this trend is the introduction of Toyota’s manufacturing system. At Toyota Motors the quality processes are so strong that their cars are virtually defect-free. This has helped Toyota tremendously in capturing market share and reducing their manufacturing costs. The Toyota manufacturing model has become a de facto standard in the automobile industry, and subsequently other industries have followed their example.