Requirements State Machine Language (RSML) evolved from statecharts during the development of the Traffic Alert and Collision Avoidance System (TCAS) II system requirements specification. This paper describes RSML and the TCAS II system requirements specification, which was reverse-engineered from pseudocode. This case study illustrates how formal methods have been applied to a safety-critical system, improving the assurance of safety in three areas: product review, process and personnel certification, and functional testing
Date of Conference: 27 Jun-1 Jul 1994