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.
,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.
, 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.