Medical Design Briefs - January 2022 - 21

VALIDATION OUTLINE
FMEA (Failure Modes and Effects Analysis)
1. Analyze process steps for the extrusion process.
2. Identify potential failure modes and their effects.
Equipment IQ/OQ
1. Identify primary process equipment required for production of requested extrusion.
2. Write IQ/OQ protocol for each piece of equipment.
3. Engineering and quality groups review and approve protocol.
4. Perform equipment IQ/OQ for required equipment.
5. Write equipment IQ/OQ report and summary.
Process OQ
1. Identify key processing parameters. Use processing knowledge as a start point.
2. Propose min/max ranges for key processing parameters.
3. Develop protocol for Process OQ.
4. Engineering and quality groups review and approve protocol.
5. Perform Process OQ. Show that the min/max ranges of parameters can meet dimensional and
visual requirements.
6. Perform statistical analysis to determine CpK for specified features.
7. Write OQ report summary.
Process PQ
1. Develop protocol for Process PQ.
2. Engineering and quality groups review and approve protocol.
3. Execute PQ runs at nominal settings (typically three setups).
4. Show that nominal settings meet both dimensional and visual product requirements.
5. Perform statistical analysis to determine CpK for specified features.
6. Write PQ report summary.
7. Ship product produced in the PQ to customer as saleable product.
Validation Report
1. IQ/OQ/PQ reports compiled in final validation report.
2. Report is reviewed and approved by engineering and quality groups.
FMEA
The FMEA is developed to analyze the steps in the extrusion process and identify potential failure
modes and their effects. Essentially, FMEA will establish the risk tolerance for each step in the
manufacturing process. It is important to take a very deliberate approach to the development of
this document by going through the following steps:
1. Identifying the process step.
2. Determining the key process input.
3. Discussing the potential failure mode.
4. Potential failure effects. (This receives a score of 1-5) = A
5. Determining the severity of the failure on the end user.
6. Discussing potential causes. (This receives a score of 1-5) = B
7. Estimating the occurrence rate of this failure mode.
8. Discuss current controls in place to mitigate this failure mode. (This receives a score of 1-5) = C
9. Multiply each of the scores given (A × B × C). Any score above 25 requires immediate attention.
Example could be as follows:
1. Identifying the process step ➝ Manufacturing
2. Determining the key process input ➝ Lack of employee training competency
3. Discussing the potential failure mode ➝ Product is nonconforming
4. Potential failure effects (This receives a score of 1-5) = 5
5. Determining the severity of the failure on the end user ➝ Failure to ID employee needs
6. Discussing potential causes (This receives a score of 1-5) = 5
7. Estimating the occurrence rate of this failure mode ➝ Competency, awareness
8. Discuss Current controls in place to mitigate this failure mode (This receives a score of 1-5) = 2
9. 5 × 5 × 2 = 50
Medical Design Briefs, January 2022
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results cannot be fully verified during
routine production by inspection and
testing (i.e., in-process dimensional
checks), then the process must be validated
according to established procedures.
That being stated, OEMs want to
be certain that when they order a particular
component, it arrives in-spec each
and every time.
As with all projects, there are many
moving pieces. Some steps move in parallel
while others move in series. The
backbone in the development of a validated
process are the three Qs, otherwise
known as IQ/OQ/PQ. Each step
toward the validated process builds on
the previous step (see the sidebar
" Validation Outline " ). The qualification
activity begins following a FMEA (failure
mode effects analysis).
IQ - Installation Qualification. This
is the verification that the manufacturing
equipment is installed correctly. For
example, is the electrical power correct
for the input of the machine? The same
questions have to be asked about all
equipment in the process, including
ovens and temperature set
points,
puller wheels, and their respective
speeds. This step is easily overlooked
but the list for validating equipment
must be complete. The important distinction
to be made in this step is that
all measurements are performed with
calibrated inspection equipment. Ex -
amples of calibrated equipment used
during this step are digital multimeters
and a calibrated stopwatch.
In order to process silicone, required
equipment includes scales (analytical
balance) to weigh raw materials, two roll
mills for raw material preparation,
extruders, curing ovens with some
means of conveying the extrudate
through the ovens, and possibly a
postcure oven for normalization. Each
piece of equipment needs to have completed
its own IQ that must be documented
for review. For example, to
qualify SiMEDEx's oven, the technicians
placed 12 thermocouples in the oven
(four on the top shelf, four on the middle
shelf, and four on the bottom shelf)
spaced equidistant from one another.
The oven was brought up to temperature
(392 °F/200 °C) for four hours and
showed that the oven held ±5 °F at each
location during the duration of the heat
soak. Another example would be showing
that the extruder screw speed reacts
accordingly to the inputs received by
the operator. For example, when you
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