Direct detection

Direct detection enables fast and reliable identification of the source of the fault.

Example

Consider a simple system, comprising an engine and an On-Off switch. To enable direct detection we need to incorporate special resilience add-ons :

A special sensor of the engine operation enables detection of situations of mal-function of the engine.
A special sensor of the On-Off state of the switch enables detection of mal-function of the switch.

If these resilience features are not added to the system, the operator will not always realize in time that the engine does not operate, and when they do realize, they need to do some troubleshooting to identify the source of the failure. In time- critical system, this might end up in an incidence.

Limitation

State sensors enable seamless identification of the component that failed, but not in all kinds of failure. Certain faults cannot be detected directly.

Examples

Leakage from a valve or a container
Malfunction of an engine
Unstable operation due to a design mistake.

Secondary risks

The resilience add-ons are also liable to fail. Special attention is required to protect from secondary faults.