Specifying the mode logic of a flight guidance system in CoRE and SCR

This paper describes the experiences of Rockwell Avionics & Communications in using the CORE and SCR methods to specify the requirements for the mode logic of a Flight Guidance System for a General Aviation class aircraft. The example was first specified by hand using the CORE method,inspected, then entered into a prototype tool supporting the SCR method provided by the Naval Research Lab. Despite careful review of the CORE model, use of the SCR tool revealed 27 errors, many of them sign& cant. Difficulties encountered, a brief analysis of the errors discovered, and issues for industrial use are discussed.