Overview of risk analysis techniques for system safety

FMEA continues to be the dominant risk analysis technique used in the medical device industry. It is time to expand our toolkit.

Risk analysis is a key element of the risk management process for medical devices according to ISO 14971¹, the International Standard for application of risk management to medical devices. Although, the standard does not prescribe any specific risk analysis technique, its companion guidance document ISO/TR 24971² details 6 different techniques³.

On the other hand, more than 100 techniques are listed in the System Safety Analysis Handbook⁴ published by the International System Safety Society (ISSS).

This presents a dilemma for risk practitioners in our industry. It is now common knowledge that FMEA alone is not sufficient for risk analysis, although it continues to dominate our current practice. But it is not clear which other techniques we should consider for a more complete risk analysis.

A more important question is which technique we should apply at different points in the lifecycle of a medical device. What is the right balance of qualitative and quantitative analysis? What level of detail is needed at each stage? How do we integrate different analyses at the system level to ensure completeness and traceability?

A first in our series on mastering risk analysis, this article offers a brief overview of 28 different risk analysis techniques⁵ identified by Clifton Ericson. We are following his book Hazard Analysis Techniques for System Safety⁶ in this series. This overview is intended to help risk practitioners expand their toolkit and develop a deeper understanding of system safety.

Let us dive in.