2 Safety Handbook - NonSIL - Library

For the development of a non-SIL classified library, this document lists measures for avoiding systematic failures during PHASE 1 up to PHASE 7.

NonSIL LIBRARIES PA Functions

MANAGEMENT/GENERAL for Libraries – Non-SIL

• Project management
  • Configuration management (CM), software support tools for CM.
  • Definition of actions and responsibilities; scheduling; training of relevant personnel
• Modification
  • Consistency checks after modifications
  • Configuration management
  • Data recording
• Documentation
  • Graphical and natural language descriptions, e.g., block diagrams, or flow diagrams.

Libraries – Non-SIL – PHASE 1 to 7

PHASE 1 - Requirements definition

• N/A

PHASE 1 - Verification activities:

• N/A

PHASE 2 - Analysis and functional design

• High-Level Design
  • No specific requirements for non-SIL

PHASE 2 - Verification activities:

• N/A

PHASE 3 - Detailed design

• Detailed Design
  • Modular approach SW (modular design) [A6]
    Selected measures (from a group of recommended measures):
  • Use of trusted/verified software elements (if available) [A6]
    The application software should:
  • be readable, understandable and testable

PHASE 3 – Verification strategies and techniques

Task: to verify the correctness and completeness of the output documents of this phase 3:

Technique/Measure:

• Checklists
  • Prepared checklists for all documented outputs of safety lifecycle phases shall be used concentrating on all safety critical issues.
  • → Refer “Checklist for Reviews” ref [A8].
• Inspection or walkthrough
  • Design descriptions shall be walked-through including a person independent of the design.
  • For SIL3 Inspection, by an independent organization using a formal procedure
  • → See ref [A34] ABB approach to avoid common cause failures in PM/ SM where the different strategy is described.

Test equipment to be used:

• Checklist (→ “Checklist for Reviews” ref [A8]).

Test documentation:

Describe details of design tests to be performed in the test plan:

• Integration Test Descriptions
  • Low-level integration test descriptions
• Design Test descriptions
  • Design Test Descriptions

PHASE 4 – Implementation / Manufacturing

• Implementation
  • Modular approach SW (modular design) [A6]
  • Coding standards [A6]
• Tools
  • No specific requirements

PHASE 4 - Verification ativities:

Task: to verify the correctness and completeness of the output documents of PHASE 4:

Technique/Measure:

• Static code analysis
  • “Static Code Analysis Guideline” ref [A17]
  • And for VHDL “FPGA Verification Methodology” ref [A24]
• Code review
  • Refer to section Code Reviews.

Test equipment to be used:

• Checklist (→ “Checklist for Reviews” ref [A8])

PHASE 5 – Module/Design and low-level integration test

• Application module testing
  • No specific requirements.

PHASE 6 – Function/Component type test

• Integration testing (ABB: Function/ Component Type Test)
  • Functional and black box testing [A7]
  • Data recording and analysis [A7]
  • Dynamic analysis and testing [A7]
  • Error guessing [A7]
  • State machine testing [A7]

PHASE 7 – Validation PTT/STT

• Validation
  • Functional test based on the requirements.

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