Formal Method Application with Safety Guarantee In Railway Signaling Control Systems

초록

As the current use of computer-based control systems becomes common, the assurance of safety and reliability needed for systems turns to difficult. When software applied to such systems is developed, the employment of formal methods in the software requirements specification and verification will provide increased safety for such applications. In this paper, to suggest a plan of formal method application for vital software of domestically installed railway signaling control systems, we compare and analyze strengths and weaknesses of existing methods for formal specification and verification. Each formal method has it own applicable section where the following effects can be maximized. For vital software of domestic train control systems, we compare several methods to find out which formal method is optimum for each case. In this paper, we proposed the plan using proper advantages of ‘Z (Zed)’, which allows high level of accuracy of requirement specification, and ‘Statemate MAGNUM’, which is a statechart-based design verification tool. This innovative compromised scheme was confirmed on the basis of actual application example and results.