6 Determine the overall oneyear system reliability for the w

6. Determine the overall one-year system reliability for the water-supply pump system shown below, if the probability of failure for each pump within a year is 3%, and individual pump failures are independent events

-----------Pump 2-------------

---------Pump 1--------- --------------------------->

-----------Pump 3 -------------

Pump 2 and 3 are in parellel. Sorry i couldnt make a better picture.

Solution

Here, the reliability is

Reliability = R(1 and (2 or 3))

= R(1) R(2 or 3)

= R(1) [R(2) +R(3) - R(2)R(3)]

As R(1) = R(2) = R(3) = 1- 0.03 = 0.97,

Reliability = 0.97*(0.97 + 0.97 - 0.97*0.97)

= 0.969127 [ANSWER]