INF3705 KEY POINTS FINAL EXAM ACTUAL

INF3705 KEY POINTS FINAL EXAM (ACTUAL / )

QUESTIONS AND VERIFIED ANSWERS GUARANTEE A+ PLUS

What are the most important dimensions of dependability? - -- -Answers----availability, reliability, safety, security, and resilience.

Sociotechnical systems include - ---Answers----computer hardware, software, and people, and are situated within an organization.

Sociotechnical systems are designed to support - --- Answers----organizational or business goals and objectives.

The use of a dependable, repeatable process is essential if - -- -Answers----faults in a system are to be minimized.

What is essential to the development of dependable systems?

• ---Answers----The use of redundancy and diversity in

hardware, software processes, and software systems.

What should the dependable, repeatable process include? - --- Answers----verification and validation activities at all stages, from requirements definition through to system implementation. 1 / 3

What do formal methods do? - ---Answers----Formal methods, where a formal model of a system is used as a basis for development, help reduce the number of specification and implementation errors in a system.

Why does formal methods have a limited take-up industry? - - --Answers----because of concerns about the cost- effectiveness of this approach.

Software reliability can be achieved by - ---Answers---- avoiding the introduction of faults, by detecting and removing faults before system deployment, and by including fault- tolerance facilities that allow the system to remain operational after a fault has caused a system failure.

Reliability requirements can be defined - ---Answers---- quantitatively in the system requirements specification.

Reliability metrics include - ---Answers----probability of failure on demand (POFOD), rate of occurrence of failure (ROCOF), and availability (AVAIL).

Functional reliability requirements are - ---Answers---- requirements for system functionality, such as checking and redundancy requirements, which help the system meet its non-functional reliability requirements. 2 / 3

Dependable system architectures are - ---Answers---- system architectures that are designed for fault tolerance.

What are the number of architectural styles support fault tolerance? - ---Answers----protection systems, self- monitoring architectures, and N-version programming.

Software diversity is difficult to achieve because - --- Answers----it is practically impossible to ensure that each version of the software is truly independent.

Dependable programming relies on - ---Answers---- including redundancy in a program as checks on the validity of inputs and the values of program variables.

Statistical testing is used to - ---Answers----estimate software reliability.

What does statistical testing rely on? - ---Answers----It relies on testing the system with test data that matches an operational profile, which reflects the distribution of inputs to the software when it is in use.

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