If a failure mode cannot be detected but the machine is critical, which strategy is NOT applicable?

When dealing with critical machines, if a failure mode is undetectable, it is essential to adopt strategies that either prevent the failure or mitigate its impact. Ignoring the failure mode is not applicable because this approach does not address the potential risks associated with the undetectable failure. By choosing to disregard it, an organization exposes itself to unexpected failures that could lead to significant operational disruptions, safety incidents, or financial losses.

In contrast, redesigning the machine could improve its reliability by eliminating the undetectable failure mode. Adding redundancy is a common practice to ensure that if one component fails, others can take over, thereby maintaining function and safety. Scheduled restoration or replacement, based on historical data, is a proactive approach that can minimize the chances of failure by ensuring that parts are serviced or replaced before they fail, even if the specific failure mode is not detectable at the moment. Thus, these strategies are applicable in managing the risks of not being able to detect a specific failure mode.