chapter 6

Question 1

Examples of system failures?

Answer 1

1. Voting system
   - outdated hardware and software
   - hacking
   - malwares or viruses
2. Denver Airport
   - baggage issues due to real world problems
   - insufficient time for development
   - significant changes in the beginning of the project
3. Airports in Hong Kong & KL
   - comprehensive system fails due to the lack of user input error consideration

Question 2

What are the reasons for system failures?

Answer 2

• lack of clear specifications and well-thought out plans
• government officials pressure in developing under low budget & short time period
• use of new technology with unknown reliability
• refuse to admit having problems in the project

Question 3

What are the case-studies?

Answer 3

1. Therac-25: Radiation overdose
   - overdose radiation treatment of patients
   - results in burn
   - problems:
   reuse of old software on new technology inadequate testing
   software bugs that deploy beams when table is not in position & ignores change in operators within consoles