Two items in parallel having a reliability of 0.90 have an overall system reliability of 0.81.

Question

Quizplus · Accepted Answer

This statement violates the principle of parallel reliability calculation. When two items are in parallel, the overall system reliability is always greater than or equal to the reliability of each individual item. Therefore, if two items have a reliability of 0.9 and are in parallel, the overall system reliability should be higher than 0.9. A system reliability of 0.81 implies that there is a significant loss of reliability, which may happen in series systems, not in parallel systems with equally reliable components.

Two Items in Parallel Having a Reliability of 0