DO-254 is a requirements-driven process-oriented safety standard used on commercial electronics that go into aircraft.
This standard helps by providing direction for design assurance of airborne electronic hardware. It also provides you with certification information from the beginning of your project through validation.
Based on their safety criticality, different parts of the aircraft are designated different Design Assurance Levels, or DALs for short. A system that is highly critical will receive a higher DAL, with DAL A reserved for the most critical systems.
This criticality is determined by a safety assessment of the aircraft and interacting systems to determine the required target failure rate. For DO-254, the difference between meeting DAL A and DAL B is minimal, so they are frequently referred to as “DAL A/B” in various writings.
Planning is a critical piece of the DO-254 certification. It’s important to document your project flow up-front and approach your certification official to gain their approval early in the project.
Typically the high-level plans are documented in the Plan for Hardware Aspects of Certification (PHAC—commonly pronounced as “pea-hack”). This plan should include all aspects of your project and how you will meet the DO-254 requirements.
The DO-254 specification utilizes a requirements-based design and verification approach. This means that the entire hardware project revolves around a formal set of high-level requirements. Before any RTL is written, each of these requirements must be written down, given a unique reference name, and reviewed for a variety of criteria including understandability, testability, verifiability, etc.
Tool assessment is another important aspect of the DO-254 process. Tools used during verification and design are capable of introducing new sources of errors and therefore must be tested to an acceptable level of confidence. Tools specifically used in verification are important to verify themselves. Should a tool fail to detect an error in the hardware being tested, the entire DO-254 process is comprised.
Want to know more? Tonex offers DO-254 Training: Avionics Hardware, a 2-day course that discusses various angles of DO-254 guidelines and will help you develop and implement this standard in your organization.
DO-254, aka Eurocae ED-80, is an official avionics guideline, which demonstrates strategies of design assurance associated with airborne electronic hardware. DO-254 covers the required information comprehensively from the conceptual design, through planning, designating, executing, verifying, to validation.
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