International Journal of Systems Applications, Engineering and Development, pp.70-77, 2017 (Peer-Reviewed Journal)
Fixed-block railway signaling systems are both regarded as Discrete Event System (DES) due to having DES-like features in their structure and safety-critical due to the fact that the occurrence of a fault may result with a huge loss of life and property. Therefore, DES-based modeling and fault diagnosis methods which are also recommended in the railway related safety standards are applicable to fixed-block signaling systems. On the other hand, the design steps of software for safety-critical systems are guided by software lifecycles. Among different lifecycle models proposed in the literature, the V-model is one of the most well-known software development lifecycle model. In this study, a modification for the Vmodel is proposed by adding a DES-based fault diagnosis step to the V-model. The proposed method is also explained with a case study on the German Ks signaling system.