The aeronautics sector is currently undergoing major development and this is expected to continue over the next few years. This means that the demand for components for this type of apparatus will grow, in contrast to other many other industry sectors and their suppliers.
But the aerospace sector has its own rules. Anyone who is considering entering this field as a designer, manufacturer, software developer, etc. needs to be aware of this if they want to meet the required standards.
In this article we are going to look at the importance of standards and regulations from the perspective of the design and development of hardware products.
How is the aerospace industry different from other industries?
In the aeronautical or aerospace industry, certain aspects are fundamental for the development of components. Without a doubt, the most well known and most important of these is safety. All aircraft, satellites and other types of craft, as well the systems that comprise them, must function without failure throughout their life. Or at least without any failures that could compromise the safety of the crew or the aircraft itself.
Following this principle of safety, duplications are frequently found within the equipment, so that in the event of a possible failure, there is the option of activating a second system to avoid any serious consequences.
These levels of quality and reliability can only be achieved if manufacturers have standardised processes in place that meet industry requirements. It is not therefore enough to manufacture reliable hardware, but the entire manufacturing process must be reliable in order to ensure that repeatability within the process is possible.
This is where DO-254 comes into play.
What is DO-254?
DO-254 or Design Assurance Guidance for Airborne Electronic Hardware is the compliance standard for the safety requirements of aircraft hardware. This standard was officially recognised by the FAA in 2005.
According to data from different industries, a DO-254 compliant project can cost between 1.5 and 4 times more than the same project without DO-254. This additional cost is usually due to a lack of knowledge of the standard and to having methodologies and processes in place that are far removed from the specifications of the document, as it is a process-oriented standard. Delays in deadlines and increases in costs can also occur as a result of failing the necessary audits and having to then reorganise and adjust the work.
It is therefore essential for companies wishing to enter this sector to have good planning and execution of the requirements specified in DO-254. Complying with the strict requirements of this sector will normally mean increases in timescales and costs but, with a work plan focused on adhering to the standard, these increases can be brought down to acceptable levels, allowing the company to still maintain its competitiveness.
Key points of the Design Assurance Guidance for Airborne Electronic Hardware Process.
Independent hardware design and verification.
Hardware design and verification must be performed independently. This provides a double layer of security as the designer will focus on the hardware meeting the requirements, while independently creating a verification system to test the hardware and verify that each of the requirements are indeed met.
The DO-254 standard also has a very requirements-based approach to both design and verification. High-level requirements should be defined from the earliest design phases, with a unique name and reference that will help to check and review them throughout the project.
Planning as a cornerstone.
Planning is a critical part of DO-254 certification. It is the first point at which the PHAC (Plan for H/W Aspects of Certification) must be submitted to the authorities (EASA, FAA, etc.), showing how DO-254 has been incorporated into the planning.
Disaggregation of the conceptual design into detailed designs.
In the conceptual design phase and in order to maintain a simpler and more manageable level, large designs will be broken down into smaller components. For every conceptual design of each of these components, the record transfer language (RTL) must already account for all the requirements, maintaining a logical traceability from the initial overall design.
Importance in process quality.
As we have seen, complying with DO-254 standards is a challenge, but it is not the only requirement that must be met. In addition to ensuring the quality of the hardware itself, it is also necessary to document how this is to be achieved. This must be done by means of a Process Assurance or Quality Assurance Plan (QA). This document must indicate which person or organisation will check that the plan is fulfilled and how this check will be carried out.
It is usual that in DO-254 certification processes, official bodies want the Quality Assurance task to be carried out by an independent and qualified organisation, one who has experience in design and verification processes (and not by someone from the team itself).
In this sense, there are differences between DO-254 and its ‘brother’ DO-178C, which is oriented to Software Quality Assurance. In this case, hardware quality assurance includes an audit of the suppliers and the processes that are generated after the hardware is procured. These processes must be properly documented and offer repeatability in accordance with project specifications.
At Centum we are experts in certification.
If your organisation needs help with the certification of on-board systems, Centum has over 10 years’ experience in providing this type of service. We have helped several organisations gain their certification, providing our own view of the whole documentation process and advising on system design wherever necessary. For further information, please do not hesitate to contact us.