Page 111 - Safety Risk Management for Medical Devices

90 Safety Risk Management for Medical Devices

• To improve consistency of ratings throughout the FMEA finish the brainstorm-
ing then identify mitigations, and then begin the ratings.
• Control the conversation and maintain focus; avoid sidebar conversations,
lengthy war stories, and egotistical debates.
• During the brainstorming part, try to maintain momentum by just capturing
the ideas and tidy up the spreadsheet after the meeting. It may be beneficial to
have a scribe to assist you.
• Use the design architecture to break the FMEA work into pieces that would fit
in one working session. Doing large FMEAs is tedious, and the process error
prone, particularly if much time has passed in between sessions.
• It might be beneficial not to start the FMEA by displaying the complete
FMEA template. Instead just focus on the items in the scope of analysis, their
Failure Modes, mechanisms of failure and effects.
• Using a database of Failure Modes and End Effects is beneficial for speeding
the work and creating consistency.

Other advices that could help with the efficiency of the FMEA process are as follows:

• Have a lead-person for the subject of analysis prefill the Failure Modes and
mechanisms of failure as seeds for discussion during the FMEA working ses-
sion. Caution should be taken in that sometimes seeing the answer to a prob-
lem could inhibit the creativity of the other team members from thinking of
new Failure Modes and Causes.
• It may be useful to have the designers keep the FMEA template in mind as
they do their design work. It could prompt them to think about Failure Modes
while they are making design decisions.

Tip Although FMEAs deal with failures under fault conditions, sometimes it may be beneficial
to list an End Effect when there is no fault. See the two examples below:
Example 1: a sensor fails to detect low blood glucose. There is no fault—the sensor simply doesn’t
have 100% sensitivity.
Example 2: a polishing step leaves a pit in a metal surface. The process didn’t fail. Normal metal sur-
faces sometimes pit.
In both examples, the End Effect is the same as if there was a failure. If there is no fault, there is also
no Cause/mechanism of failure. In such cases write “No Fault” in the column “Causes/Mechanisms of
Failure.” This would be an extension of the FMEA for the benefit of risk management.

12.5 FMEA IN THE CONTEXT OF RISK MANAGEMENT

The hazard analysis process uses a confluence of FMEAs from lower system-levels into the
RACT. The relation between FMEAs and the RACT is shown in the following figures.