Methodologies Used in Safety-Critical Development

Ever since we use computers to perform control technical tasks, our goal has been to ensure that their operational safety meets the desired standards, both from a hardware and software point of view. We can easily see that above a level that is difficult to define, the complexity of the software is so high that it is impossible to see trough and follow it and, as we wrote in several previous articles, to test it sufficiently. In this paper, after a brief historical summary, we will deal with the development methodologies used today, highlight their appropriate field of application and their main characteristics. We present examples of where and how each discussed methodology can be applied in aviation.