Software-Reliability
Question 1 |
The following table shoes the time between failures for a software system
The reliability of the system for one hour of operation assuming an exponential model is
0.45 | |
0.63 | |
0.84 | |
0.95 |
Question 1 Explanation:
MIBF = ∑(Start of downtime - Start of uptime)/No. of failures
MIBF = (6+4+8+5+6)/5 = 29/5
The probability or reliability that the product will work for a defined period of time without failure is given by
R(T) = exp(-T/MTBF); T = 1 hour
R(1) = e(-1/(29/5)) = e(-5/29) = 0.84
MIBF = (6+4+8+5+6)/5 = 29/5
The probability or reliability that the product will work for a defined period of time without failure is given by
R(T) = exp(-T/MTBF); T = 1 hour
R(1) = e(-1/(29/5)) = e(-5/29) = 0.84
Question 2 |
Consider a software program that is artificially seeded with 100 faults. While testing this program, 159 faults are detected, out of which 75 faults are from those artificially seeded faults. Assuming that both real and seeded faults are of same nature and have same distribution, the estimated number of undetected real faults is ______.
28 | |
175 | |
56 | |
84 |
Question 2 Explanation:
Total faults detected = 159
Real faults detected among all detected faults = 159 - 75 = 84
Since probability distribution is same, total number of real faults is (100/75)*84 = 112
Undetected real faults = 112- 84 = 28
Real faults detected among all detected faults = 159 - 75 = 84
Since probability distribution is same, total number of real faults is (100/75)*84 = 112
Undetected real faults = 112- 84 = 28
Question 3 |
Software reliability is described with respect to
(A) Execution Time
(B) Calendar Time
(C) Clock Time
Choose the correct answer from the options given below:
(A) and (B) only | |
(B) and (C) only | |
(A), (B) and (C)
| |
(A) and (C) only |
Question 3 Explanation:
Software reliability testing is a field of software-testing that relates to testing a software's ability to function(which is related execution), given environmental conditions, for a particular amount of time(related to clock). Software reliability testing helps discover many problems in the software design and functionality.
Software reliability is also related to the ability of software to execute for a long period of time without any failure, which in turn related to calendar time.
Software reliability is also related to the ability of software to execute for a long period of time without any failure, which in turn related to calendar time.
There are 3 questions to complete.