10 déc. Minimum Software Life Cycle Data That Is Submitted tO Certification Authority . 45 .. EUROCAE EDB is identical to RTCA DOB. the production of software for airborne systems and equipment used on aircraft or. Overview. ▫ DOB – Software Considerations in Airborne. Systems and Equipment Certification. ▫ Standard of RTCA Incorporation (in Europe it is ED-. Introduction to DOB – Software Considerations in Airborne Systems and Equipment Certification. 1. Overview of DOB Swamy S M.
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DOB, Software Considerations in Airborne Systems and Equipment Certification is a guideline dealing with the safety of safety-critical software used in certain airborne systems.
Although technically a guideline, it was a de facto standard considerrations developing avionics software systems until it was replaced in by DOC.
The FAA applies DOB as the document it uses for guidance to determine if the software will perform reliably in an airborne environment,  when specified by the Technical Standard Order TSO for which certification is sought.
The failure conditions are categorized by their effects on the aircraft, crew, and passengers.
DO-178C → Code Coverage
DOB alone is not intended to guarantee software safety aspects. Safety attributes in the design and as implemented as functionality must receive additional mandatory system safety tasks to drive equupment show objective evidence of meeting explicit certiication requirements. Typically IEEE STD Software Safety Plans are allocated and software safety analyses tasks are accomplished in sequential steps requirements analysis, top level design analysis, detailed design analysis, code level analysis, test analysis and change analysis.
These software safety tasks and artifacts are integral supporting parts of the process for hazard severity and DAL determination to cretification documented in system safety assessments SSA. The certification authorities require and DOB specifies the correct DAL be established using these comprehensive analyses methods to establish the software level A-E.
Any software that commands, controls, and monitors safety-critical functions should receive the highest DAL – Level A.
It is the software safety analyses that drive the system safety assessments that considedations the DAL that drives the appropriate level of rigor in DOB. The system safety assessments combined with methods such as SAE ARP A determine the after mitigation DAL and may allow reduction of the DOB software level objectives to be satisfied if redundancy, design safety features and other architectural forms of hazard mitigation are in requirements driven by the safety analyses.
Therefore, DOB central theme is design assurance and verification after the prerequisite safety requirements have been established. The number of objectives to be satisfied eventually with independence is determined by the software level A-E. The phrase “with independence” refers to a separation of responsibilities where the objectivity of the verification and validation processes is ensured by virtue of their “independence” from the software development team.
For objectives that must be satisfied with independence, the person verifying the item such as a requirement or source code may not be the person who authored the item and this separation must be clearly documented.
Processes are intended to support the objectives, according to the software level A through D—Level E was outside the purview of DOB.
Processes are described as abstract areas of work in DOB, and it is up to the planners of a real project to define and document the specifics of how a process will be carried out. On a real project, the actual activities that will be done in the context equipmenr a process must be shown to support the objectives. These activities are defined by the project planners as part of the Planning process. This objective-based nature of DOB allows a great deal of flexibility in regard to following different styles of software life cycle.
Once an activity within a process has been defined, it is generally expected that the project respect that documented activity within its softwzre. Furthermore, processes and their concrete activities must have well defined entry and exit criteria, according to DOB, and a project must show that it is respecting those criteria as it performs the activities in the process.
The intention of DOB was not to be prescriptive. There are many possible and acceptable ways for a real project to define these aspects. This can be difficult the first time a company attempts to develop a civil avionics system under this standard, and has created a niche market for DOB training and consulting.
DOB is not intended as certificaiton software development standard; it is software assurance using a set of tasks to meet objectives and levels of rigor. Traceability osftware system requirements to all source code or executable object code is typically required depending on software level.
DOB – Wikipedia
Typically used software development process:. Analysis of all code and traceability from tests and results to all requirements is typically required depending on software level.
Documents maintained by the configuration management process:. This process handles problem reports, changes and related activities. The configuration management process typically provides archive and revision identification of:.
This process performs reviews and audits to show compliance with DOB. The interface to the certification authority is also handled by the quality assurance process. Software can automate, assist or otherwise handle or help in the DOB processes. All tools used for DOB development must be part of the certification process. Tools generating embedded code are qualified as development toolswith the same constraints certivication the embedded code.
Tools used to verify the code simulators, test execution tool, coverage tools, reporting tools, etc. A third party tool can be qualified as a verification tool, but development tools must have been developed following the DO process.
DOC Software Considerations in Airborne Systems and Equipment Certification → Code Coverage
Companies providing these kind of tools as COTS are subject to audits from the certification authorities, to which they give complete access to source code, specifications and all certification artifacts. Requirements traceability is concerned with documenting the life of a requirement.
It should be possible to trace back to the origin of each requirement and every change made to the requirement should therefore be documented in order to achieve traceability. Even the use of the requirement after the implemented features have been deployed and used should be traceable. VDC Research notes that DOB has become “somewhat antiquated” in that it is not adapting well to the needs and preferences of today’s engineers.
In the same report, they also note that DOC seems well-poised to sofyware this issue. From Wikipedia, the free encyclopedia. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.