DO-178c: What is DO-178c and how is it different from DO-178B?
In aviation, software bugs don’t just crash programs; they can cost lives. That’s why safety isn’t optional.
Over the years, the need to control aircraft software development has grown stronger. Whether you build an autopilot or a warning system, your code must follow strict rules. Those rules aren’t just internal checklists; they’re industry-wide guidelines used across the globe.
One of the most widely followed standards today is DO-178C. It defines how aviation software should be planned, written, tested, and reviewed — all before a plane ever leaves the ground.
This blog explains what DO-178C compliance is, how it has evolved from DO-178B, the core components of DO-178C, and why it is important in the avionics industry.
A Quick Overview of DO-178B and DO-178C
What is DO-178B?
DO-178B, officially known as RTCA DO-178B / EUROCAE ED-12B, is a set of guidelines for airborne software development. Mainly, it outlines the guidelines for designing, developing, and testing the airborne software to ensure it meets the safety standards and rules set by aviation authorities. By following DO-178B, the chances of an aircraft’s system failure can be reduced.
DO-178B covers:
- A step-by-step process for the avionics software development
- A clear guide for requirements management
- traceability between requirements and test cases
- Basic guidelines for reviews, testing, and configuration control
What is DO-178C? (An Updated Version of DO-178B)
The way software is developed has changed a lot since the 90s. Teams now use automated tools, model-based designs, and object-oriented programming. These weren’t well supported under DO-178B. As a result, applying the standard started to feel forced and unclear.
To fill this gap, an updated version of DO-178B, which is DO-178C, was introduced in 2011. It covers updated guidelines to use modern tools and technologies during the software development of the aviation system.
DO-178C introduces:
- Clearer rules for using software development tools
- Support for model-based development and code generation
- Guidance for object-oriented programming in safety-critical systems
- Better handling of software reuse across projects
- Improved traceability between requirements, code, and tests
- Add-on documents (DO-330, DO-331, DO-332, DO-333) for specific use cases
For any new software used in flight-critical systems, certification based on DO-178C compliance is now expected. Without it, getting approval from authorities like the FAA or EASA is nearly impossible.
DO-178C vs. DO-178B: Key Differences That Matter
Feature / Area | DO-178B | DO-178C |
|---|---|---|
Release Year | 1992 | 2011 |
Tool Qualification | Basic guidelines were provided. | Comprehensive guidelines are provided in the DO-330 supplement document. |
Support for Model-Based Development | Not introduced | DO-331 supplement document covers a detailed guide on model-based development. |
Support for Object-Oriented Programming | Not addressed directly | Included via DO-332 |
Formal Methods Support | Not mentioned | Defined in DO-333 |
Handling of Modern Dev Tools | Limited | Fully supported with a clear structure |
Software Reuse Guidance | Minimal | Improved coverage for reusable components |
Requirements Management | Provides basic definitions for requirements management. | Provides comprehensive guidelines for requirements management, analysis, validation, etc. |
Traceability | Introduced basic traceability. | Provides guidelines to achieve end-to-end traceability. |
Certification Usage Today | Still used for legacy systems | Required for new certifications |
Core Components of DO-178C Compliance
Below are the main components of the standard that teams need to apply:
1. Software Planning
The first phase of the DO-178C is the planning phase, in which the development team prepares various documents for how software should be designed, developed, reviewed, and tested. These plans are often reviewed by certification authorities, so getting them right at the beginning is critical.
You can check the guidelines that the FAA follows while approving certification for aviation software. So, developing a proper plan at the beginning is important.
2. Collecting and Managing Software Requirements
Once planning is done, it is important to gather clear and testable requirements. Without having clear requirements, it becomes very hard to ensure whether the software meets the end goals.
For teams using Azure DevOps, Modern Requirements4DevOps helps manage and link requirements directly to design, code, and test cases. This keeps everything in one place and simplifies traceability across the entire project.
Also read: How to Choose a Requirements Management Tool in 6 Steps
3. Software Design and Development
In this phase, development teams prepare the system design for the software architecture based on the requirements defined in the previous step. After that, code implementation gets started according to the DO-178C standard.
Teams also need to ensure that everything is documented in this step, and there should be a clear link between each requirement, its design, the code, and related test cases.
4. Software Verification and Validation
During the software verification, developers and testers check whether the software meets all requirements defined previously. On the other hand, during validation, teams use different methodologies like unit testing, integration testing, system testing, etc., to determine whether the software works as expected.
5. Change Management
It is very important to record and track every change, whether it’s in the code, document, or test data. It is useful to prevent mistakes and unapproved updates. For that, teams need tools with built-in version control, and Modern Requirements4DevOps offers exactly that.
6. Quality Assurance
This step is about checking whether the team followed the defined process. It includes internal audits, reporting process issues, and making sure the overall workflow stays in line with the project’s safety and regulatory goals.
Why DO-178C Compliance is Important and what it helps you achieve
- Required for Certification Approval: If your software is going to be used in aviation systems, you must follow the DO-178C guidelines to get certifications from regulatory authorities like the FAA and EASA. If software doesn’t meet the standard, it won’t get clearance for flight-critical use.
- Increases Software Safety and Reliability: By adhering to the DO-178C standard, organizations can build software that has very few chances of failure. According to AFuzion, companies applying DO-178C practices have seen up to 90% fewer bugs found in live systems.
- Improves Software Reusability: As DO-178C enforces teams to use modern engineering principles like model-based development, object-oriented programming, etc., it promotes software reusability.
- Makes Global Product Delivery Easier: Since DO-178C is accepted in both the U.S. and European markets, meeting this standard helps companies avoid region-specific rework.
- Helps Manage Future Updates: Because everything is documented and traceable, adding new features or fixing defects later becomes easier without affecting safety approvals
Common Challenges in DO-178C Implementation
DO-178C just explains the standards and processes for airborne software development, but while following them in real-time, the team often faces a few challenges. Here, we have covered a few of them with solutions to overcome them.
- Heavy Documentation Load: In each phase, from planning to verification, teams are required to create and manage documents. If the proper tool is not used for document management, the team might miss important updates. By using a document management system that offers version control and allows teams to manage documents collaboratively, they can solve this challenge.
- Traceability Gaps: A few teams rely on spreadsheets to link requirements. If these links are broken or poorly managed, it can lead to certification delays or rework.
- Tool Qualification Confusion: Many teams use tools that are not qualified under DO-330, which can introduce risks.
- Working Across Disconnected Systems: Developers, testers, and QA teams often work in different tools. This makes it hard to manage changes, track progress, or prepare for audits.
To overcome these challenges, teams need to choose a tool that supports:
- DO-330 tool qualification readiness
- Built-in Requirements Management
- End-to-End Traceability
- Version Control and Change Tracking
- Real-Time Collaboration and Reviews
- Document management system
- Report Generation for Audits
- AI to streamline requirements management
If your team is already using Azure DevOps, Modern Requirements4DevOps offers all of this in a single integrated setup, reducing the complexities in compliance management and helping teams stay audit-ready.
TL;DR
If your organization is developing aviation software and wants to get certified by the FAA or EASA, stick to DO-178 while developing airborne software. It is recommended that you give proper DO-178C training to your team so they understand the process from the beginning.
Choosing the right tool is equally as important as following the DO-178C process. Without a proper tool, you can’t manage documents, prepare reports for the certifications, and check whether the end product meets the stakeholders’ expectations.
