Software Engineering

Dependability and Security Specification

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is not a functional reliability requirement for a system?
Checking requirements
Recovery requirements
Redundancy requirements
Ambiguous requirements
Explanation:
All the options are correct except option d.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The aim of preliminary risk analysis and assessment process is to derive security requirements for the system as a whole.
True
False
Explanation:
In preliminary risk analysis stage, decisions on the detailed system requirements, the system design, or the implementation technology have not been made.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
How many stages are there in Risk-driven requirements specification?
three
four
five
six
Explanation:
These include Risk identification, Risk analysis, Risk reduction and Risk decomposition
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Consider a case where the failure of the system causes damage to the system itself or it data. What type of failure is being described here?
Loss of service
Incorrect service delivery
System/data corruption
None of the mentioned
Explanation:
None.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
At which stage of risk analysis specification, the additional security requirements take account of the technologies used in building the system and system design and implementation decisions?
Preliminary risk analysis
Life-cycle risk analysis
Operational risk analysis
All of the mentioned
Explanation:
This risk assessment takes place during the system development life cycle after design choices have been made..
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Consider a case where the system is unavailable and cannot deliver its services to users. What type of failure is being described here?
Loss of service
Incorrect service delivery
System/data corruption
None of the mentioned
Explanation:
One may separate this into loss of critical services and loss of non-critical services, where the consequences of a failure in non-critical services are less than the consequences of critical service failure.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
To specify security requirements, one should identify the risks that are to be dealt with.
True
False
Explanation:
To specify security requirements, one should identify the assets that are to be dealt with.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Which reliability requirements are concerned with maintaining copies of the system?
Checking requirements
Recovery requirements
Redundancy requirements
Ambiguous requirements
Explanation:
These requirements are geared to helping the system recover after a failure has occurred.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
POFOD stands for
Possibility of failure of data
Probability of failure of data
Possibility of failure on demand
Probability of failure on demand
Explanation:
None.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Which reliability metric sets out the probable number of system failures that are likely to be observed relative to a certain time period?
POFOD
ROCOF
AVAIL
None of the mentioned
Explanation:
Rate of occurrence of failures (ROCOF) sets out the probable number of system failures that are likely to be observed relative to the number of system executions.