Software Safety in Subway and Air Traffic Control Applications

This paper presents the problem of using software in critical applications, which are the ones that, in case of faults in their working, can cause serious consequences as material damages or even deaths. There are detailed the basic architecture of two of the most important applications existent today. These applications include subway supervision and control systems and air traffic control. In these two areas there are highlighted the main software characteristics that impact directly or indirectly in the safety of the system, operators and environment. There are also presented the main features that can be used in order to improve the safety of such applications.