A design framework for identifying optimum services using choreography and model transformation

Service Oriented Architecture (SOA) has become an effective approach for implementing loosely-coupled and flexible systems based on a set of services. However, despite the increasing popularity of the SOA approach, no comprehensive methodology is currently available to identify “optimum” services. Difficulties include the abstraction gap between the business process model and service interface design as well as service quality trade-offs that affect the identification of the “optimum” services. The selection of these “optimum” services implies that SOA implementation should be driven by the business model and should also consider the appropriate level of granularity. The objective of this thesis is to identify the optimum service interface designs by bridging the abstraction gap and balancing the trade-offs between service quality attributes. This thesis proposes a framework using the choreography concept to bridge the abstraction gap between the business process model and service interface design together with service quality metrics to evaluate service quality attributes. The framework generates the service interface design automatically based on a chain of model transformations from a business process model through the use of the choreography concept (service choreography model). The framework also develops a service quality model to measure service granularity and service quality attributes of complexity, cohesion and coupling. These measurements aim to evaluate service interface designs and then select the optimum service interface design. Throughout this thesis, a pragmatic approach is used to validate the transformation models applying three application scenarios and evaluating consistency. The service quality model will be evaluated empirically using the generated service interface designs. Despite several remaining challenges for service-oriented systems to identify “optimum” services, this thesis demonstrates that optimum services can be effective