A short introduction to risk analysis and FMEA for medical devices

FMEA stands for Failure Mode Effects Analysis and is the denomination of a method that aims to increase the reliability of products or processes (P-FMEA). The method of FMEA is documented in the standard IEC 60812:2006. The term is sometimes used in place of risk analysis or risk management within the medical device industry. It is important to note that the FMEA, as it is known in the literature and in the standard, cannot be said to meet the requirements of risk management found in the Medical Device Directive.

The FMEA is based on how a component can fail and what consequences the failure will lead to for the system as a whole. Since the components are being analysed, the components of the product need to be known, i.e. construction should have progressed quite a bit before it makes sense to start the FMEA.

Let’s use an example. We have constructed a boat that has a propeller. The boat has a seal on the propeller shaft. In the FMEA, we specifically study the seal and try to identify how it may fail, so-called failure modes. A failure mode that we find is “breakage”, i.e. the seal breaks. The purpose of the seal is to prevent water from leaking into the boat, which it will if the seal is broken. The local effect is ingress of water. For the system as a whole, it means that the boat might sink, which may be considered a fairly serious systemic effect on a boat. If the probability is extremely low, we may not do more with this problem, but if the probability is slightly higher, then we may take action, such as e.g. have double seal, make checks or purchase seals with a high safety factor against breakage. All such measures are also suitable in the FMEA.

FMEA is usually documented in a table. For every line you write, you get an RPN number, a Risk Priority Number, that is used to compare risks and indicate which risks should be dealt with first. FMEA typically does not contain a limit between acceptable and unacceptable risk.