Redundant software systems is a safety feature. Unrealistic reliability or safety estimates can come from lack of understanding, carelessness, or intentional misrepresentation. Often political pressure to produce inflated safety predictions. Professional Techniques Software engineering and professional responsibility . Important to use good software engineering techniques at all stages of development.
Professionals have respon to study and use techniques and tools that are available.
Learning enough about the application field and software systems to understand potential problems and to do a good job. User interfaces and human factors . Pilot needs feedback to understand what the automated system is doing at any time. A workload that is too low can be dangerous. Redundancy and self checking .