Systems engineering, and especially the modeling of safety critical systems, needs proper means for early Validation and Verification (V&V) to detect critical issues as soon as possible. The objective of our work is to identify a verifiable subset of SysML that is usable by system engineers, while still amenable to automatic transformation towards formal verification tools. As we are interested in proving safety properties expressed using invariants on states, we consider the B method for this purpose. Our approach consists in an alignment of SysML concepts with an identified subset of the B method, using semantic similarities between both languages. We define a restricted SysML extended by a lightweight profile and a transformation towards the B method for V&V purposes. The obtained process is applied to a simplified concrete case study from the railway industry: a SysML model is designed with safety properties, then automatically transformed into B, and finally imported into Atelier-B for automated proof of the properties.