1. To not successfully complete or pass a particular stage, level, or phase of a process, project, or assessment
If you fail the phase, you will need to repeat it before moving forward.
Se você falhar na fase, terá que repeti-la antes de avançar.
2. To not meet the required standards or criteria during a specific phase of development, testing, or evaluation
The software failed the phase of user acceptance testing.
O software falhou na fase de testes de aceitação do usuário.