High-integrity software is software whose failure may cause serious damage with possible "life-threatening consequences". "Integrity is important as it demonstrates the safety, security, and maintainability of code." Examples of high-integrity software are nuclear reactor control, avionics software, automotive safety-critical software and process control software.
[H]igh integrity means that the code:
Does what it should.
Can be tested.
Has security features.
Lacks security vulnerabilities.
Is easy to understand and follow logically.
Is easy to edit and upgrade without introducing new errors.
A number of standards are applicable to high-integrity software, including:
DO-178C, Software Considerations in Airborne Systems and Equipment Certification
CENELEC EN 50128, Railway applications – Communication, signalling and processing systems – Software for railway control and protection systems
IEC 61508, Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems (E/E/PE, or E/E/PES)
ISO 26262, Road Vehicles – Functional Safety (especially 'part 6' of the standard, which is titled "Product development at the software level"
Wallace, Dolores R.; Ippolito, Laura M.; Kuhn, D. Richard (1992). High Integrity Software Standards and Guidelines(PDF). National Institute of Standards and Technology. Retrieved February 15, 2022.