EN 50128

SOFTWARE TESTING TOOLS FOR EN 50128 / 50657

Achieve compliance with certified Software Testing and Static Analysis

EN 50128

SOFTWARE TESTING TOOLS FOR EN 50128 / 50657

Achieve compliance with certified Software Testing and Static Analysis

EN 50128 / 50657

The software safety standard EN 50128 originates from the European Committee for Electrotechnical Standardisation, or CENELEC. Its full title is ‘Railway applications. Communications, signalling and processing systems. Software for railway control and protection systems’. The International published version of the CENELEC EN 50128 standard is IEC 62279. The content of both publications is identical

The standard requires that all systems with safety implications and which contain software should be assigned a Software Integrity Level (SIL), ranging from a value of 0 to 4. The standard then details in a number of ‘normative’ and ‘informative’ ways, the software development activities appropriate to each SIL which should be carried out, and evidence for the completion of which should be generated.

The standard EN 50657:2017 specifies the process and technical requirements for the development of software for programmable electronic systems for use in rolling stock applications. The standard adapts EN 50128:2011 for the application in the Rolling Stock domain, but is shares a lot in common including the definition of the Software Integrity Levels (SIL).

Testing tools for compliance with EN 50128 / 50657 recommendations

QA Systems enables organisations to accelerate EN 50128 / 50657 compliance with automated static analysis and software testing tools:

STATISCHE ANALYSE

QA-MISRA

Detaillierte Tiefenanalyse für C/C++-Code

CANTATA TEST ARCHITECT

Software-Architektur: verstehen, definieren und kontrollieren

SOURCE-CODE-METRIKEN

Automatisierte Source-Code-Metriken für C/C++

SOFTWARE TESTS

CANTATA

Automatisierte Unit- und Integrationstests für C/C++-Code

CANTATA TEAM REPORTING

Add-on für die Zusammenarbeit von verteilten Teams

ADATEST 95

Automatisierte Unit- und Integrationstests für Ada-Code

Tool Certification & Qualification

EN 50128 and 50657 (section 6.1.4.2) states that tools, hardware or software, used for testing shall be shown to be suitable for the purpose. QA Systems’ dynamic testing tool Cantata has been classified and certified by SGS-TÜV GmbH, an independent third party certification body for functional safety, accredited by Deutsche Akkreditierungsstelle GmbH (DAkkS). Cantata has been classified as a class T2 tool, and is usable in development of safety related software according to EN 50128:2011 and 50657:2017 up to Software Safety Integrity Level (SW-SIL) 4.

For our static analysis tool QA-MISRA, our tool Qualification Support Kit (QSK) automatically executes a full tool qualification verification test suite on the installed tool configuration and generates the necessary reports for EN 50128 / 50657 tool qualification.

These tool kits for EN 50128 / 50657 are available to ease our customers’ path to certification. They contain everything needed to prove that Cantata and QA-MISRA provide the required confidence in the use of software tools under EN 50128 / 50657 recommendations as well as comprehensive and detailed guidance on how to use them to comply with the required software verification activities of EN 50128 / 50657.

Please contact us for more information about these certification kits.

Cantata Certificate

Software testing for EN 50128 / 50657 compliance

EN 50128 / 50657 recommends unit and integration testing. Cantata enables developers to verify EN 50128 / 50657 compliant C and C++ code on host native and embedded target platforms.

Cantata helps accelerate compliance with the standard’s software testing requirements by automating:

  • Test framework generation
  • Test case generation
  • Test execution
  • Results diagnostics and report generation

Our EN 50128 / 50657 Standard Briefing traces the requirements of EN 50128, identifying the scope of those which are supported by Cantata and identifies how the requirements are supported by Cantata.

Please contact us for more information on Cantata for EN 50128 / 50657.

The EN 50128 / 50657 software testing recommendations by SIL and where these are supported by Cantata are summarised in the tables below:

EN 50128 / 50657 Table A. 5 Verification and Testing

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
2. Static Analysis HR HR HR HR Yes
3. Dynamic Analysis and Testing HR HR HR HR Yes
4. Metrics R R R R Yes
5. Traceability R HR HR M M Yes
6. Software Error Effect Analysis R R HR HR Yes
7. Test Coverage for code R HR HR HR HR Yes
8. Functional/ Black-box Testing HR HR HR M M Yes
9. Performance Testing HR HR HR HR Yes
10. Interface Testing HR HR HR HR HR Yes

EN 50128 / 50657 Table A. 6 – Integration

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
1. Functional and Black-box Testing HR HR HR HR HR Yes
2. Performance Testing R R HR HR Yes

EN 50128 / 50657 Table A. 7 – Overall Software Testing

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
1. Performance Testing HR HR M M Yes
2. Functional and Black-box Testing HR HR HR M M Yes

EN 50128 / 50657 Table A. 8 – Software Analysis Techniques

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
1. Static Software Analysis R HR HR HR HR Yes
2. Dynamic Software Analysis R R HR HR Yes
5. Software Error Effect Analysis R R HR HR Yes

EN 50128 / 50657 Table A. 13 – Dynamic Analysis and Testing

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
1. Test Case Execution from Boundary Value HR HR HR HR Yes
2. Test Case Execution from Error Guessing R R R R R Yes
3. Test Case Execution from Error Seeding R R R R Yes
5. Equivalence Classes and Input Partition Testing R R R HR HR Yes
6. Structure-Based Testing R R HR HR Yes

EN 50128 / 50657 Table A. 14 – Functional/Black Box Test

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
3. Boundary Value Analysis R HR HR HR HR Yes
4. Equivalence Classes and Input Partition Testing R HR HR HR HR Yes

EN 50128 Table A. 15 – Textual Programming Languages

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
4. C or C++ R R R R R Yes
7. Assembler R R R R R Yes

EN 50128 / 50657 Table A. 18 – Performance Testing

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
2. Response Timing and Memory Constraints HR HR HR HR Yes

EN 50128 / 50657 Table A. 20 – Components

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
1. Information Hiding Yes
2. Information Encapsulation R HR HR HR HR Yes
3. Parameter Number Limit R R R R R Yes
4. Fully Defined Interface R HR HR M M Yes

EN 50128 / 50657 Table A. 21 – Test Coverage for Code

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4 Cantata
1. Statement R HR HR HR HR Yes
2. Branch R R HR HR Yes
3. Compound Condition R R HR HR Yes
4. Data flow R R HR HR Yes
5. Path R R HR HR Yes

Start a free trial to evaluate Cantata using your code.

Static Analysis for EN 50128 / 50657 compliance

While Static Analysis is not Mandatory at any EN 50128 / 50657 SIL, it is the only practical way in which a coding standard (which is Mandatory for SIL 3 and 4) can be enforced.

Within the standard, Phase 7.5 (Software Component Implementation) together with Annex A (Criteria for the Selection of Techniques and Measures) address software development, placing requirements on the initiation of software development; software architectural design and software unit design and implementation. This is the main area where the Static Analysis tools are used; however, some of the information generated from the tools can also be used to assist in later stages, particularly testing.

Please contact us for more information on the static analysis tool QA-MISRA for EN50128 / 50657.

The following tables are from the normative Annex A of EN50128 / 50657 and show where Static Analysis can be used to meet the required technique or measurement.

EN 50128 / 50657 Table A. 4 – Software Design and Implementation

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4
4. Modular Approach HR M M M M
5. Components HR HR HR HR HR
6. Design and Coding Standards HR HR HR M M
7. Analyzable Programs HR HR HR HR HR
8. Strongly Typed Programming Language R HR HR HR HR
9. Structured Programming R HR HR HR HR
11. Language Subset HR HR

EN 50128 / 50657 Table A. 5 – Verification and Testing

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4
2. Static Analysis HR HR HR HR
4. Metrics R R R R

EN 50128 / 50657 Table A. 8 – Software Analysis Techniques

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4
1. Static Software Analysis R HR HR HR HR

EN 50128 / 50657 Table A. 12 – Coding Standards

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4
1. Coding Standard HR HR HR M M
2. Coding Style Guide HR HR HR HR HR
3. No Dynamic Objects R R HR HR
4. No Dynamic Variables R R HR HR
5. Limited Use of Pointers R R HR HR
6. Limited Use of Recursion R R HR HR
7. No Unconditional Jumps HR HR HR HR
8. Limited size and complexity of Functions,
Subroutines and Methods
HR HR HR HR HR
9. Entry / Exit Point strategy for Functions,
Subroutines and Methods
R HR HR HR HR
10. Limited number of subroutine parameters R R R R R
11. Limited use of Global Variables HR HR HR M M

EN 50128 / 50657 Table A. 19 – Static Analysis

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4
3. Control Flow Analysis HR HR HR HR
4. Data Flow Analysis HR HR HR HR

EN 50128 / 50657 Table A. 20 – Components

Methods SIL 0 SIL 1 SIL 2 SIL 3 SIL 4
1. Information Hiding
2. Information Encapsulation R HR HR HR HR
3. Parameter Number Limit R R R R R

Start a free trial of QA-MISRA to evaluate your code against MISRA, AUTOSAR, CERT C/C++, CWE and other coding standards to ensure automated compliance with ISO EN 50128 / 50657.