RTCA / DO-178B/C Certification with the LDRA tool suite
Overview
What is RTCA/DO-178B/C?
The international avionics standard for safety-critical software, RTCA/DO-178B/C Software Considerations in Airborne Systems and Equipment Certification Requirements, imposes very strict Dynamic Coverage Analysis requirements. The LDRA tool suite provides a comprehensive set of powerful analysis facilities for assisting companies around the globe to meet DO-178B/C requirements.
As the implementation of DO-178B/C becomes more widespread it is essential that the choice of tool is based on known expertise. The LDRA tool suite provides a proven solution and has assisted both airborne and ground based systems to meet the DO-178B standard.
The LDRA tool suite enables organisations to work towards:
Tool Selection
When selecting a tool to assist in achieving DO-178B compliance, the following criteria should be considered:
- Does the tool provide a complete "end-to-end" Requirements Traceability capability to enable linkage and documentation from all levels to the source code and associated test cases.
- Does the tool enable analysis for all Structural Coverage Analysis requirements as laid out in section 6.4.4.2 of the standard?
- Is there tool availability for a wide range of programming languages?
- Has the tool been utilised in this manner successfully already?
- Will the supplier assist in tool qualification?
- Is the supplier both flexible and extensive enough to meet changing requirements?
- Is the tool easy to use?
The LDRA answer to all of the above questions is YES.
Flexible Tool Support
DO-178B is evolving in response to experience gained by the FAA when applying the standard to real-world applications. LDRA has the skills and expertise to adapt the LDRA tool suite to meet these changing requirements and is committed to providing a powerful tool suite that will verify compliance with the standard both now, and in the future.
For example the FAA is currently requesting coverage information on combinations of constructs that only the LDRA tool suite can measure. In addition DO-178B may require coverage of implied XOR in the C language. LDRA is already committed to existing customers to meet this requirement if this is the case.
DO-178B Structural Coverage Analysis Requirements
Following is the pertinent extract from DO-178B:
6.4.4.2 Structural Coverage Analysis
The objective of this analysis is to determine which code structure was not exercised by the requirements-based test procedures. The requirements-based test cases may not have completely exercised the code structure, so structural coverage analysis is performed and additional verification produced to provide structural coverage. Guidance includes:
- The analysis should confirm the degree of structural coverage appropriate to the software level.
- The structural coverage analysis should normally be performed on the source code. If DO-178B Level A verification is required then additional analysis must be undertaken on the object code to verify the correctness of the compiler-generated code sequences. Both of these analyses may be performed with the LDRA tool suite.
- The analysis should confirm data coupling and control coupling between the code components.
These requirements are summarised as follows:
| Item | Description | DO-178B Ref. No. | DO-178B Level A | DO-178B Level B | DO-178B |
| 5 | MC/DC is achieved | 6.4.4.2 | Satisfied with Independence | Not Required | Not Required |
| 6 | Decision Coverage is satisfied | 6.4.4.2.a 6.4.4.2.b |
Satisfied with Independence | Satisfied with Independence | Not Required |
| 7 | Statement Coverage is satisfied | 6.4.4.2.a 6.4.4.2.b |
Satisfied with Independence | Satisfied with Independence | Satisfied |
| 8 | Data Coupling and Control Coupling is achieved | 6.4.4.2.c | Satisfied with Independence | Satisfied with Independence | Satisfied |
Note: Items 5, 6, 7 and 8 are not required for DO-178B Level D.
The LDRA Tool Suite DO-178B Coverage Measures
The LDRA tool suite delivers the coverage measurement criterion as laid down in DO-178B:
DO-178B Level A Measurement:
- Modified Condition Decision Coverage (MC/DC)
- Branch/Decision Coverage (TER2)
- Statement Coverage (TER1)
DO-178B Level B Measurement:
- Branch/Decision Coverage (TER2)
- Statement Coverage (TER1)
DO-178B Level C Measurement:
- Statement Coverage (TER1)
Other Coverage Measures:
- LCSAJ Coverage (TER3)
- Branch Condition Coverage (BCC)
- Branch Condition Combination Coverage (BCCC)
The LDRA tool suite is currently the only analysis tool to offer such comprehensive assistance in meeting DO-178B.
Note also that there is currently no other tool that provides the code analysis capabilities required to test Assembler code to DO-178B standards.
Is the tool suite easy to use?
The tool suite's ease of use is a key issue when incorporating it into project procedures. The LDRA tool suite has been specifically enhanced to enable simple measurement of conformance to the various levels of DO-178B. Reports are specifically tailored to give users DO-178B information quickly and concisely, speeding up the testing procedure. Reports can be produced in either ASCII or HTML. Either format can be easily incorporated into a Word processor or DTP system. HTML has the added advantage of links and the ability to publish on the Internet or an intranet.
Proven Track Record in RTCA/DO-178B Certification
The LDRA tool suite is being utilised by companies around the world to meet RTCA/DO-178B and other avionics standards. A cross-section of clients currently utilising the LDRA tool suite include:
| ADA India Airbus France ALT Software Inc USA Artus France Aviapribor CJSC Russia BAE Systems UK Bechtel Bettis Inc USA Bell Helicopters Textron USA Boeing USA Crane Aerospace ELDEC USA C-S Canada USA Data Systems & Solutions UK Dunlop Aviation Coventry Elbit Systems Ltd Israel eSysTech USA Fairchild Controls USA Fiat Avio Italy GE Aviation UK GE Aviation USA Goodrich Sensors and Integrated Systems USA Hamilton Sundstrand USA Honeywell Aerospace UK |
Honeywell Aerospace USA Israel Aircraft Industries Israel McLaren Electronic Systems Ltd UK Mindready Solutions Inc USA NEC Aerospace Systems Japan Northrop Grumman USA Pacific Scientific EKD USA Raytheon Space and Airborne Systems USA Rockwell Collins USA Rolls-Royce Derby Securaplane Technologies Inc USA SENER Spain Smiths Aerospace S-TEC Corporation USA Sumitomo Precision Products Co Ltd Japan TEC-Masters USA Thales Avionics France Thales Avionics Ltd UK Trimble Military and Advanced Systems Inc USA TRW USA Ultra Electronics High Wycombe Ultra Electronics Datel Preston Westland Helicopters Yeovil |
