Problem 1
Identify six consumer products that are likely to be controlled by safety- critical software systems.
Problem 3
In the insulin pump system, the user has to change the needle and insulin supply at regular intervals and may also change the maximum single dose and the maximum daily dose that may be administered. Suggest three user errors that might occur and propose safety requirements that would avoid these errors resulting in an accident.
Problem 4
A safety-critical software system for managing roller coasters controls two main components: \- The lock and release of the roller coaster harness which is supposed to keep riders in place as the coaster performs sharp and sudden moves. The roller coaster could not move with any unlocked harnesses. \- The minimum and maximum speeds of the roller coaster as it moves along the various segments of the ride to prevent derailing, given the number of people riding the roller coaster. Identify three hazards that may arise in this system. For each hazard, suggest a defensive requirement that will reduce the probability that these hazards will result in an accident. Explain why your suggested defense is likely to reduce the risk associated with the hazard.
Problem 6
Explain when it may be cost-effective to use formal specification and verification in the development of safety-critical software systems. Why do you think that some critical systems engineers are against the use of formal methods?
Problem 7
Explain why using model checking is sometimes a more cost-effective approach to verification than verifying a program's correctness against a formal specification.
Problem 8
List four types of systems that may require software safety cases, explaining why safety cases are required.
Problem 10
Should software engineers working on the specification and development of safety-related systems be professionally certified or licensed in some way? Explain your reasoning.
