“…Nevertheless, for urban railway systems, which are more independent and closed systems, the B method has been accepted and has been applied in such critical systems and some key components. The early success stories are [12]: KVB, an Automatic Train Protection system for SNCF since 1993; SAET-METEOR [13], a driverless Train Automation and Operation system in metro Line 14 in Paris in 1998; Roissy VAL, a Section Automatic Pilot system for light driverless shuttle for Paris-Roissy airport in 2006. A recent application is the COPPILOT system [14], [15], which is a metro platform screen door controlling system of the ClearSy company.…”