RTCA DO-254, Design Assurance Guidance for Airborne Electronic Hardware is a document that serves as a guidepost for the development of aeronautical electronic hardware. It categorizes electronic hardware items as part of the simple group or the complex group. it has performed faultlessly in every type of foreseen operating condition and shown no indications of unknown behavior. Contrastingly, an item is deemed complex if no test or analysis is able to ensure its faultless functional performance, in which case, assurance should be sought through supplemental methods.
The whitepaper is hinged on the principle that hardware design and hardware verification are two different phases of the development process. One critical responsibility of the hardware designer is ensuring that the hardware design will satisfy established requirements. At the same time, the verification engineer will produce a verification plan that will enable the testing of the hardware to check if it satisfies each of its derived requirements.
The first step in the development process is planning, in which the design authority (the company behind the project) defines its approach towards the certification. After the plan is completed, it will be prepared for review by the authorities. This plan will mainly include the approach that the developer intends to take in keeping with the guidelines contained in DO-254.
Validation and Verification
The process for validating hardware development assures that hardware item-derived requirements are accurate as well as complete as per the system requirements which the particular hardware item has been allotted. When hardware requirements being confirmed come from system requirements, it is not categorized as a hardware process, but rather as a system process. Hence, when hardware requirements are derived by hardware processes, they have to be correlated with system processes to know if they are consistent with the system requirements. As per the whitepaper’s processes, a requirement is complete when all defined properties are vital and all of these vital properties have been enumerated and exhaustively discussed; on the other hand, a requirement is correct when it is defined without any degree of ambiguity and the defined properties are have absolutely no errors.
The verification process guarantees that the hardware item implementation satisfies derived requirements and all other hardware requirements. Verification is done in through a qualitative review, quantitative analysis, and functional testing.
Basic Electronic Hardware Application
Essentially, for rudimentary electronic hardware, the verification process that supports the basic classification requires three steps: definition, performance, and recording. However, the hardware design assurance level will determine how rigorous and thorough this verification should be. Examination of test coverage for Level A or B should confirm that every node and interconnection has been tested; as to Level C, the single requisite is to demonstrate the right operation for each combination and permutation of conditions applied solely on the device inputs; and for Level D, indirect tests may be conducted on the system of which the item forms part. If a simple electronic device certification is sought, documentation, while minimal, should still be provided.