UNDERSTAND THE CONCEPT
For independent, active parallel components where any one can meet the full requirement, system reliability is 1 − the product of the component failure probabilities. This expression assumes all branches operate for the mission and does not by itself model standby switching.
Redundancy can be weakened by common power, control systems, environmental exposure or maintenance errors. Capacity also matters: two half-capacity pumps may not meet a full-capacity success criterion when one fails. Record the actual operating configuration before assigning a model.
Questions to take back to your team
- Can one branch meet the required output?
- Is the arrangement active or standby?
- Which common dependencies affect both branches?
Further reading
Explore the primary references below. Requirements and applicability depend on your organization and jurisdiction.
