In this paper, we use a combination of the SysML/KAOS requirements engineering method, an extension of SysML, with concepts of the KAOS goal model, and of the B System formal method. Translation rules from a SysML/KAOS goal model to a B System specification have been defined. They allow to obtain a skeleton of the B System specification. To complete it, we have defined a language to express the domain model associated to the goal model. The translation of this domain model gives the structural part of the B System specification. The contribution of this paper is the description of translation rules from SysML/KAOS domain models to B System specifications. We also present the formal verification of these rules and we describe an open source tool that implements the languages and the rules. Finally, we provide a review of the application of the SysML/KAOS method on case studies such as for the formal specification of the hybrid ERTMS/ETCS level 3 standard.