Managing the Testing Process: Practical Tools and Techniques for Managing Hardware and Software Testing

1.6. Exercises

1. Why is it impossible for testing to find all the bugs in a system? Why might it not be necessary for a program to be completely free of defects before it is delivered to its customers? To what extent can testing be used to validate that the program is fit for its purpose?^[]

   ^[] This exercise was contributed by Dr. Deepti Suri of Milwaukee School of Engineering.

2. Suppose that you go to an office supply store, buy a printer, and bring it back to your office. You connect it to one of the computers on the office network, and it works fine from that computer. However, when you try to share the printer with other systems on the network, you can't get the printer to work properly from the other workstations. After spending some time trying to figure it out, you find out from technical support that the pr inter does not support printing from a network, but only locally. Is this a bug (i.e., a quality problem) with the printer? Explain your answer in terms of reasonable customer expectations of quality.

3. Prepare a risk analysis for a calculator program, focusing on behavioral testing during a system test phase. (Suggestion: Imagine any of the popular PC operating systems such as Windows, Linux, and Solaris that include calculators.)

   • Use the informal risk analysis technique.

   • Use the formal Failure Mode and Effect Anal ysis technique.

4. Prepare a schedule and budget for testing the calculator based on the assumption that you will do the testing yourself.

   • Approximately what percentage ...