Question

A product has three components, A, B, and C, with reliabilities of 0.95, 0.98, and 0.995. Engineers intend to put a redundant component A that has reliability 0.70. With this change, system reliability will fall:

1. by 20% fall
2. by 10% or less
3. rise cannot determine from the information provided
4. None of these

Answer 1

Rise

Explanation:

After the insertion of the redundant component A, if A fails, the redundant component has a 0.70 percent of not failing. Therefore, the original reliability for component A increases:

`R_(an) = 0.95+(1-0.95)*0.70\\R_(an) = 0.95+(1-0.95)*0.70\\R_(an) = 0.985`

If the reliability for component A increases, as a result, the system reliability also rises as a whole.