WEBVTT

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A control should explain how it changes
the failure pathway.

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Prevention reduces the chance of failure.

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Detection identifies a problem.

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Response determines what happens next.

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For a mixing failure, a justified design
or operating control may prevent

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an unsuitable condition.

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An alarm may detect it, but only an
effective response can limit the

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consequence.

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The three blocks are complementary; none
is automatically adequate for

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every process.

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Our fictional action is to verify the
agitator-status indication and the

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defined response to loss of mixing.

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Engineering owns the technical check and
operations owns the response

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procedure and training.

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The verification plan records the
challenge method and the expected

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behaviour.

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Quality oversight reviews the evidence
through the site system.

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Action closed should mean the intended
result was demonstrated,

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not merely that a document was drafted.

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Adding a control can introduce a new
dependency.

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An alarm may depend on power,
configuration, sensor health or a shared

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signal.

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If the alarm and controller use the same
failed sensor,

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apparent independence may be misleading.

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The diagram shows a common sensor feeding
two functions to make that

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concern visible.

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Examine the actual architecture and
challenge assumptions before taking

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credit for an independent protective
layer.

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After controls are implemented, evaluate
what risk remains and who can accept it.

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Record assumptions and review triggers.

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Quality risk management does not excuse a
practice that conflicts with

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applicable requirements.

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For the activity, select one failure mode
and propose a prevention,

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detection and response strategy.

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Then identify evidence for effectiveness
and one new risk introduced by

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your proposal.

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This turns a list of actions into an
auditable argument.