Functional Safety — Safety Instrumented Systems for the Process Industry Sector — Part 1: Framework, Definitions, System, Hardware and Application Programming Requirements
Specifies requirements for the specification, design, installation, operation and maintenance of a safety instrumented system, so that it can be relied on to achieve or maintain a safe state of the process. It is the process-sector implementation of IEC 61508.
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Scope & applicability
Safety instrumented functions — the interlocks and trips that act without the operator — across their whole safety lifecycle, with a required safety integrity level derived from risk rather than asserted. It is distinct from the basic process control system and from alarm management: an alarm asks a person to act, a safety instrumented function acts itself.
Key requirements
- Hazard and risk assessment establishing the required safety integrity level for each safety instrumented function
- A safety requirements specification stating the function and its integrity target before design
- Design and engineering with separation from the basic process control system, and defined proof-test intervals
- Operation and maintenance including proof testing, bypass control and management of change
- Consolidated edition 2.1 comprises the 2016 second edition, corrigendum 1 (2016) and amendment 1 (2017)
Implementation tips
- A safety integrity level is derived from a risk assessment, not chosen — an SIL asserted without the assessment behind it cannot be defended and usually cannot be met by the design that claims it
- Bypasses are where safety instrumented systems actually fail: control the authorisation, the duration and the compensating measure, and record every one
Where this control fails
live FDA enforcementLive FDA recalls SPEQ maps to this standard’s topics — a SPEQ interpretation, not an FDA classification.
IEC 61511-1:2016+A1:2017: frequently asked questions
Quick answers to common questions about IEC 61511-1:2016+A1:2017.
What is IEC 61511-1:2016+A1:2017?
IEC 61511-1:2016+A1:2017 — Functional Safety — Safety Instrumented Systems for the Process Industry Sector — Part 1: Framework, Definitions, System, Hardware and Application Programming Requirements — is a standard issued by the International Electrotechnical Commission. Specifies requirements for the specification, design, installation, operation and maintenance of a safety instrumented system, so that it can be relied on to achieve or maintain a safe state of the process. It is the process-sector implementation of IEC 61508.
Who does IEC 61511-1:2016+A1:2017 apply to?
Safety instrumented functions — the interlocks and trips that act without the operator — across their whole safety lifecycle, with a required safety integrity level derived from risk rather than asserted. It is distinct from the basic process control system and from alarm management: an alarm asks a person to act, a safety instrumented function acts itself.
What are the key requirements of IEC 61511-1:2016+A1:2017?
IEC 61511-1:2016+A1:2017 requires, among other things: Hazard and risk assessment establishing the required safety integrity level for each safety instrumented function; A safety requirements specification stating the function and its integrity target before design; Design and engineering with separation from the basic process control system, and defined proof-test intervals; Operation and maintenance including proof testing, bypass control and management of change.
When was IEC 61511-1:2016+A1:2017 last updated?
The current version of IEC 61511-1:2016+A1:2017 dates from August 2017.
This standard in practice
Recall domain is a SPEQ mapping of this standard’s topics, not an FDA classification.