A computer has an MTBF of 10000 h Assuming constant failure

A computer has an MTBF of 10000 h. Assuming constant failure rate, what is its reliability for a 10000- h mission? A receiver has an estimated failure rate of 100 x 10E-6 failures per hour. Assuming constant failure rate, what are its MTBF and its reliability for a 100-h mission? A 2000-h mission? A 5000-h? A 10000-h mission?

Solution

Mean time between failures =10000

Or if no of computers failing = x, then x follows a Poisson distribution with mean 1 in 10000 hours.

Reqd prob = P(x=1) = 0.3679

Thus is it reliable for 10000 hours for nearly 0.6321 or 63.21%

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Failure rate = 100 x10^-6 failures

n = 100 hours

Mean value = np

i) for 100 hours mean = 100x10^-4 failures = 0.01

ii) 2000 hours         = 0.2

iii) 5000 hours       = 0.5

iv) 10000 hours     = 1