Software Engineering, Exam, May 23 1998.

• Answers may be written in Swedish or English, or any reasonable mixture of those.

• Leave a good margin; don't use a red pen. Write clearly, I'm not good at guessing half-readable Swedish words.

• If something is unclear, make reasonable assumptions and write them down. I'll be in my office (phone 4717606) and come by to answer questions around 10:30.

• A checklist of common mistakes that cost points:
  • Answer all 14 questions. A bad answer never gives less points than no answer.
  • Read the question again after you have written the answer and verify that you answered all parts.
  • In particular, don't forget to give an example if that is requested, and make it a concrete one.
  • Avoid unclear or missing argumentation; risky words are 'of course', 'self-evident', 'better', 'wrong', ...
  • When a question asks you to compare two things, make sure to highlight the contrasts: their differences.

• The sum of the points for the exam questions is 55. The total numer of points for the course is 100. A G-mark requires ca 55-60 points, a VG ca 75.

• For each question, I give its points and a maximal length of the answer. The optimal length is usually around half of this maximum.

• Results will be posted on the WWW and are available at David Sonnek's guest lecture, June 3rd, 13-15, room 1211.

• Don't forget to fill in the course evaluation.

• Good luck!

1. Describe how prototyping can be incorporated in a software development process based on the waterfall model. Make a distinction between evolutionary and throw-away prototyping. (6p, 1.5 page).

2. Describe the role of system models in the requirements analysis process. (4p, 1 page).

3. Requirements specifications are most often written in natural language. Give (at least) two alternatives. Discuss the advantages and disadvantages of the three languages. (4p, 1 page).

4. What is a software design? Of what parts does it consist? (Books have been written about this question, but here you must show that you can identify the essential parts. 5p, 1 page).

5. Describe how the reliability metrics Rate of Failure Occurrence (ROCOF) and Mean Time to Failure (MTTF) are related. Give examples that show how they are used for different purposes. (3p, 0.7 page).

6. Relate and contrast the following concepts: failure, fault, mishap, hazard, risk. Use a concrete example in which these concepts occur. (4p, 1 page).

7. What is the safe state of a railway crossing? Is this state still safe after 10 minutes? Motivate your answers. (2p, 0.5 page).

8. What is a test case, other than the input data? What sources for these remaining parts of a test case may be available? (4p, 0.7 page).

9. Explain what is meant by statistical testing. Explain why it is meaningful to perform statistical testing on a (usually deterministic) system. Use a concrete example (4p, 1 page).

10. Contrast maintenance of physical products (houses, bikes) to software maintenance. (2p, 0.5 page).

11. What are the major techical and non-technical factors which hinder widespread reuse of components and sub-systems? (3p, 0.7 page).

12. Give examples of internal and external attributes of software products. Compare their role in quality assessment. (3p, 0.5 page).

13. a. Describe the five levels of the SEI process maturity model. (2p, 0.7 page).
    b. Summarize the problems and criticisms regarding this model. (4p, 1 page).

14. Describe in a few sentences how Brooks arrives at the conclusion that there can be no more Silver Bullet. What are the weakest (yet not very weak) points in his argumentation? (5p, 1 page).