Service architectures are an increasingly adopted architectural approach for solving the Enterprise Application Integration (EAI) problem originated by business process automation requirements. In previous work, we developed a methodological framework for the designing of service architectures for EAI. The framework is structured in a layered architecture called LABAS, and is distinguished by using architectural abstractions in different layers. This paper describes the pattern-based techniques used in LABAS for service identification, for transformation from business models to service architectures and for architecture modifications.