Challenges in updating military safety-critical hardware

Herein, we describe challenges and suggest solutions when upgrading military safety-critical hardware where RTCA/DO-254 [1] was never applied but is required now and not only for application-specific integrated circuits (ASICs), programmable logic devices (PLDs), and complex commercial-off-the-shelf (COTS) but for all hardware. Several challenges relate to modification to previously developed hardware resulting from hardware or technology enhancements, or procurement difficulties.