Software Engineering, Exam, March 17, 2010.

• Start by reading all the questions, to see if anything is unclear. I plan to visit around 9:30 to clarify questions.
  

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

• Start each answer on a new page. Please hand in the pages in the correct order.

• For each question, I give its points and a maximal length of the answer. The optimal length is usually around half of this maximum. (This does not include drawings.)

• A checklist of common mistakes that cost points:
  • Answer all 12 questions. A bad answer never gives less points than no answer.
  • Read the question again after you have written the answer. Verify that you have actually answered the question. Verify that you answered all parts. Verify that you have not hidden the answer between many other irrelevant comments about the topic.
  • In particular, don't forget to give an example if that is requested, and make it a concrete one.
  • When a question asks you to compare two things A and B, make sure to highlight the contrasts: their differences. I do not want a full description of A and a full description of B, leaving it to me to find the differences.

• Good luck!
  

1. Given a fixed budget, explain the benefits of incremental development on
   
   1. usability
   2. functionality
   3. presence of faults
   in the delivered product (4 points, 1.5 page)
   
   
2. What reasons could the customer have to impose process requirements? (3 points, 1 page)
   
   
3. What are the purposes of making system models during requirements engineering? Distinguish between informal and formal models. (5 points, 2 pages)
   
   
4. System development can be divided into requirements engineering, design, implementation, and so on.
   1. In this context, what are the steps of designing a software system? (5 points, 1.5 page)
      
   2. Why is there no hard border between requirements specification and design?
      (2 points, 0.5 page)
      
   3. How is the design process altered if many reusable components are available?
      (3 points, 1 page)
      
      
5. Give three examples of tasks that are usually performed by the middle layer in a logical three-tier architecture. (3 points, 1 pages)
   
   
   Turn!
   
   
   
6. It is sometimes a requirement for a safety critical system that certain features of the programming language are not used. Give 4 examples of such features and motivate for each feature why it can cause a hazard or make the system impossible to verify. (4 points, 1.5 pages)
   
   
7. In some safety-critical systems, there are several (N) copies of the same hardware. In software, the corresponding concept is N-version programming. Explain how the differences between hardware and software cause differences in the application/behaviour/effectivity of redundant hardware versus N-version programming. (4 points, 1 page)
   
   
8. Describe (at least) five different test methods. For each method, mention
       * its goal, and
       * (briefly) how it is done, and
       * what CASE-tools are useful, or even necessary.
   (10 points, 3 pages)
   
   
9. Give three examples of requirements that cannot be tested, but that can be verified by inspection. (3 points, 1 page)
   
   
10. Give a brief description of the Scrum process.  (4 points, 1.5 page)
    
    
11. Describe four different methods to estimate the cost of a project. What input does each method need (i.e., what information do you need in order to apply each method)? (4 points, 1.5 page)
    
    
12. Describe the tasks associated to securing the quality of a project, and by who, how and when they are carried out in relation to the project. (6 points, 2 pages)