Software-Engineering

Question 15

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

A	0.45
B	0.63
C	0.84
D	0.95

Software-EngineeringSoftware-ReliabilityGATE 2007-IT

Question 15 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

Correct Answer: C

Question 15 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