Pragmatic granularity decision for right-grained services in service-oriented modelling

Abstract

The identification of right-grained services is important in leading a successful service orientation because it has a direct impact on two major goals: the composability of loosely-coupled services and the reusability of individual services in different contexts. Although the concept of service orientation has been intensely debated in recent years, a unified methodic approach for identifying services has not yet been identified. In this paper, we suggest a formal approach to identify services at the right level of granularity from the business process model abstraction. Our approach adopts the concept of activity allocation based on the locality principle for defining loosely-coupled services. The method utilising the concept of graph partitioning can minimise the network roundtrip costs incurred during the service execution. If we can define activities into a service as cohesively as possible, we can identify the reusable and self-contained services so as to reduce the coupling of remote tasks and increase the local task cohesion.