Abstract
Service-oriented architecture (SOA) can use fine grained a well as coarse grained service interfaces. It appeared that coarse-grained interfaces are usually preferable. The fine-grained interfaces have some technical advantages - e.g. the applicability of object-oriented attitudes (compare SOAP-RPC protocol) but it often leads to SOA antipatterns like Chatty Services and Fine-Grained Services. We discuss further advantages of coarse-grained service interfaces: problem and user orientation, stability, and advanced variants of information hiding. We show that such advantages are enabled if a specific variant of SOA - software confederation - is used. This architecture - software confederation - has many practical advantages. We show that some service types used in confederations can be a kernel of design patterns for service-oriented architectures. The patterns discussed in this paper are based on so-called architecture services supporting the integration of components (services) into SOA. Software confederations can be built as agile systems - as systems easily adaptable to the changing environment and business needs. They can support the implementation of agile business processes.