Modes of Failure

 

The novel oxygen delivery device has multiple sources of error that can potentially result in catastrophic failure which, in the context of this system, is patient death. These failures can be classified under two primary categories: user error and device failure. This section describes each mode of potential failure and what the team has done or plans to do to address them. We performed a failure modes and effects analysis (FMEA) on the new device to quantify the potential for failure as well as quantified the total potential for failure over the entire life of this device versus the existing device via fault tree analysis (FTA).

 

An FMEA involves identifying all potential modes of failure in a system and rating the probability of failure, severity of failure, and probability of detection on a scale from 1-10. The product of the three ratings is taken to identify a hazard index that ranges from 0-1000 with a higher value indicating a higher priority for implementing controls. Current controls are listed along with recommended action to reduce the probability of failure.

 

An FTA involves quantifying the probability of an error occuring and combining those errors via a series of "and" or "or" gates, depending on whether both events need to happen or either event happening will trigger a system failure. All failures converge to a top event, which is the worst case scenario outcome if the system fails. In this case, this top failure is patient death.