Introduction to Software Testing

A software analogue ...

• The software analogue is called N-version programming (NVP):
• Have N teams each write a version of the required program independently given the same requirements.
• Run all N programs; when results differ, take a vote.

NVP under scrutiny

• What are the potential problems with NVP?
• Software failures are not like hardware failures. All software failures are design failures, not material failures.
• Often, programmers make the same kinds of mistakes, misinterpretations, and have similar biases.
• Requirements are often misleading, wrong, vague, etc
• What if only one of the N teams actually has the correct interpretation!