Why DO 178C ?
Several supporting papers were generated over the years to clarify the some aspects which were not specified in DO178 B.
- Advancement in SW Engineering / New Technologies (like MBD, OOT, Formal Methods…)
- CAST Papers (30 as of today)
- Tool Qualification –NOT same as on-board embedded software
- Inconsistency between DO-178B and DO-278 (CNS/ATM)
- Use of COTS –Safety (& Cost) concerns with previously developed software
Software Levels of DO178C
Sources to develop DO178C ?
The DO178C is made with help of different Do source documents and those are
- DO 178B
- DO 278
- CAST Papers
- RTCA Document DO 248B
- ARP 4754A
- FAA Order 8110.49
- Issue Papers.
What are the special Interests/Topics in DO 178C?
In DO178C, the following topics were special interest due to the fact that many development departments within the avionics industry are influenced by or want to use these technologies .
- MBD – Model Based Development & Verification
- OOT – Object Oriented Tools/Languages
- COTS – Commercial Of the Shelf Software
- Formal Methods.
Planning Process in D0178C?
The planning process in the Do178 C is as follows
- Establishment of SW Plans
- Definition of the SW life cycle Environment
- Consideration of Language and Compiler
- Establishment of Software standards
- Review and Assurance of the Software Planning.
Design Process in DO178C?
The Design Process in the DO178C is as follows.
- Development of Software Architecture.
- Development of Low Level Requirements
- Development of Derived Requirements
- Considerations for User-Modifiable Software
- Deactivated Code
Verification Process in DO178C?
The Verification Process in Do178C is as follows
- Reviews and Analysis of High Level Requirements
- Reviews and Analysis of Low Level Requirements
- Reviews and Analysis of Software Architecture
- Reviews and Analysis of Source Code.
- Hardware/Software Integration Testing
- Software Integration Testing
- Low Level Testing
- Requirement Base Test Coverage Analysis
- Structural Coverage Analysis
- Reviews and Analysis OF Test Cases
- Reviews of Procedures and Results
- Software Development Process Traceability
- Software Verification Process Traceability
- Verification of Parameter Data Items.
What is Model Based Development & Verification?
This Supplement deal with Model Based Development & Verification and was written to add, modify and substitute the objectives defined in DO 178C, the models are used.
- To Develop an unambiguous expression of requirements and architecture
- To assist in automated code generation
- To assist in automation test generation
- Analysis tool for the verification of the requirements and architecture
For every model, the requirement’s needs to be identified from which the model is developed, for which the model is developed.
The following aspects described in the MBD&V supplement should be highlighted
- In the planning phase and in the planning documentation, the usage of models need to be explained and the models needs to categorized as a specification or design model
- Software Model standards are required.
- Simulation can be used in design models to support testing and analysis methods.
- Usage of model simulation for verification of the model and verification of the executable object code.