AbstractThe Event-B method is a formal approach to modelling systems, using refinement. Initial specification is done at a high level of abstraction; detail is added in refinement steps as the development proceeds toward implementation. In software systems that use concurrent processing it is necessary to provide details of concurrent features before implementation. Our contribution is to show how Event-B models can be linked to concurrent, object-oriented implementations using an intermediate, object-oriented style specification notation. To validate our approach and gain further insight we automated the translation process with an Eclipse plug-in which produces an Event-B model and Java code. We call the new notation Object-oriented Concurrent-B (OC-B). The notation facilitates specification of the concurrent aspects of a development, and facilitates reasoning about concurrency issues in an abstract manner. We abstract away implementation details, such as locking, and provide the developer with a clear view of atomicity using labelled atomic clauses. We build on techniques introduced in UML-B to model object-oriented developments, introducing non-atomic operations and features for specifying implementation level details.