Safety in the Matrix
Siemens innovative approach to functional safety helps meet the requirements of the oil and gas
industry by maximizing safety while also ensuring high availability and reduced costs
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Functional safety as a layer of protection
Plant and
Emergency
Response
Mitigate
Emergency response layer
Containment,
Dike, Vessel
Passive protection layer
Fire and Gas
System
Active protection layer
Incident
SIS
Emergency
Shutdown
System
Emergency
Safety layer
Shutdown
Prevent
Operator
Intervention
Operator
Process alarm
Process control layer
Intervention
BPCS
Normal
Process Value
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behavior
Process control layer
How do we ensure safety integrity for the SIS?
Plant lifecycle
Failure causes
Competence
+
Functional safety
management
+
Technical
requirements
•
•
Robust design
Robust processes
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Analysis
Specifications
Design & implementation
Installation & startup
Operation & maintenance
Changes after start-up
The lifecycle approach according to functional safety standard IEC 61511
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Focussing on software
The lifecycle approach for the application program
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IEC61511 encourages the following best practice for application software
The selected design method and application language (LVL or FPL) should possess features that facilitate
• Abstraction, modularity and other features which control complexity;
• Expression of functionality, information flow; sequencing requirements; operation within defined time
constraints; freedom from indeterminate behavior; assurance that internal data items are not erroneously
duplicated, all used data types are defined and appropriate action occurs when data is out of range or bad;
design assumptions and their dependencies.
• Comprehension by developers and others
• Verification and validation, including coverage of the application software code, functional
coverage of the integrated application, the interface with the SIS and its application specific
hardware configuration.
• Application software modification. Such features include modularity,
traceability and documentation.
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IEC61511-1 Clause 12.4.2.3
Traditional Approach to implementing SIS logic
• Requires some interpretation of cause and effect into LD, FB or CFC
• Not immediately intuitive - even if logically structured and well commented
• Custom engineering required (overrides, bypasses, operator graphics, reports)
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Alternative “Safety Matrix” approach
• Little or no interpretation required
• Verification and validation is less onerous
• Relatively easy to understand for all stakeholders
• Mechanisms for overrides, bypasses, operator graphics, reports are already included
© Siemens AG 2015. All rights reserved.
Safety Matrix Components
Safety Matrix Editor
For creating and editing the Safety Matrix logic on an
external workstation outside a STEP 7 or PCS 7
environment
Safety Matrix Engineering Tool
For creating, configuring, compiling, downloading
and online monitoring of the Safety Matrix with in
STEP 7 environment
Safety Matrix Viewer
For operator control and visualization of the Safety
Matrix within PCS7 OS environment with different
operator control levels
© Siemens AG 2015. All rights reserved.
Design & engineering performance
Integrated safety lifecycle tools
© Siemens AG 2015. All rights reserved.
Design & engineering performance
Integrated safety lifecycle tools
The realization phase
• The SIMATIC Safety Matrix as engineering tool
• Configuration of the safety functions using
the Cause & Effects Method
• Automatic TÜV-certified creation of the Safety Logic
from the Cause & Effect Matrix
• Easy configuration without special
programming knowledge
• Online monitoring mode for verification and validation
• Reduces systematic errors
• Simplifies engineering, verification and validation
• Saves time, improves safety
© Siemens AG 2015. All rights reserved.
Design & engineering performance
Integrated safety lifecycle tools
Operation & maintenance, modification
• Online view of the signal status, Cause & Effects
Automatic integration in PCS 7
• First up alarm display and storage
• Supports operator bypass, reset, override
and parameter changes
• Sequence of event recording
• Automatic report of operation functions
• Automatic version tracking
• Automatic documentation of changes
• Reduces systematic errors
• Simplifies engineering, verification and validation
• Improves operator efficiency
• Saves time, improves safety
© Siemens AG 2015. All rights reserved.
We are happy to answer your questions!
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2015. All rights reserved.