Institute of Measurement and Control. Functional Safety 2016
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Figure 1 Failure types
Systematic Capability
IEC 61508:2010 Edition 2 introduced the term “systematic capability” back in 2010 to be used to
quantify the capability of a SIF Element (such as a sensor, logic solver or actuator) in terms of its
systematic safety integrity.
Systematic Capability is defined as "...a measure (expressed on a scale of SC 1 to SC 4) of the
confidence that the systematic safety integrity of an element meets the requirements of the specified
SIL, in respect of the specified element safety function..."
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The term “SIL Capability” has long been used as a way of referring to the systematic safety integrity of
specific devices within a safety instrumented function. SIL capability, however, is not a term
specifically defined by IEC 61508 & IEC 61511 and its specific meaning is often misunderstood or
misused. The introduction of the term “systematic capability” gives a better, more specific way of
expressing how well a SIF element will perform in terms of systematic failures.
Developing a Product to Achieve a Specific Systematic Capability
Meeting the general requirements of IEC 61508
To claim a level of systematic capability the broader requirements of the IEC 61508 standard must be
addressed. Such as:-
·
Lifecycle approach and functional safety management
·
Competence and Competency Management
·
Processes, Procedures, Planning
·
Roles, Responsibilities
·
Verification , Validation, Testing
·
Auditing, Assessment,
·
Planning, Documentation,
·
The ‘V’ model.
·
Safety Requirement Specifications
·
Application software Safety requirement specifications etc , etc
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IEC 61508-4 IEC:2010 Para 3.5.9