DO-178B OVERVIEW & PROCESS FLOW
The DO-178B guidelines describe objectives for software life-cycle processes, activities and design considerations for achieving those objectives, and proving that the objectives have been satisfied. The majority of DO-178B is dedicated to describing a sequential waterfall development methodology for new, custom-built avionics software. This approach is a requirements-based development and verification methodology that includes a number of alternative methods for satisfying the objectives. DO-178B is not a strict or detailed standard; it is a general framework for developing provable, high-reliability software consistently. Developers of avionics equipment and software must comply with the guidance provided by DO-178B.
Military equipment manufacturers, for example, have complied with military-mandated software standards including DOD-STD-2167a, MIL-STD-498, and ISO/IEC-12207; now they must comply with DO-178B for a number of reasons:
• Operation within civilian airspace
• DOD-mandated cost reduction measures
• Combined usage of avionics for both military and commercial purposes
Commercial software manufacturers are also examining the certification guidelines, as they look to aerospace products to expand their markets share. Ten years ago, there were very few DO-178B compliant COTS products. Today, the world is different: dozens of products including RTOS’s, drivers, graphics packages, core boards, development tools, and testing tools are all compliant or certifiable to DO-178B. These manufacturers hope to provide software that has proven compliance “out of the box”, and has also proven reliability exceeding that of their competitors.