Using A Rigorous Approach for Engineering Web Service Compositions: A Case Study Paper Presentation and Discussion Heberth Braga G. Ribeiro

Authors Howard Foster, Sebastian Uchitel, Jeff Magee, Jeff Kramer at the Imperial College London (UK) Michael Hu at the Police Information Technology Organization (UK) 9/5/20152

Introduction The case study is taken from a national development currently underway by the Police IT Organization (PITO) in the UK The view of the project is to consolidate distributed national police services and to form a set of core processes The contribution of the study is to support a series of different police enquiry types Study of some scenarios described within the scope of interacting police enquiry types 9/5/2015http://

Background A series of services requires management and coordination Implementations needs to be constructed for a series of differing scenarios Specification perspective – focus is on service interactions Is important to build the web service compositions correctly, verify the process before deployment, etc... 9/5/2015http://

Background 9/5/2015http:// An Approach to Rigorous Web Service Composition Engineering

Scope and Requirements Compositions consists of an orchestration of a number of web services implemented basic enquiry Core enquiry processes running on a central business process architecture 9/5/2015http:// PITO Web Services Architecture Scope

Interaction Specifications 9/5/2015http:// Interactions are added to support the steps described in the scenario The composition service in this scenario is form from a single “police enquiry” The policy enquiry composition makes a request using key search criteria Basic Message Sequence Chart(bMSC) assumes that each enquiry is performed sequentially from the central service

Interaction Specifications 9/5/2015http:// Concurrency Composition Improvement

Implementations 9/5/2015http:// Web Service Compositions  The process consists of a series of BPEL4WS process statements

Implementations Web Service Coreography  Defines a kind of policy for “rules of engagement”  The police enquiry composition interacts with other services  Adressing choreography take us back to the designer  Provides a global view of requirements for one or more scenarios 9/5/2015http://

Implementations 9/5/2015http:// Overview of Choreography Architecture in Elaborated Composition Scenario

Analysis and Evaluation of Approach Effort required to adress issues that arise when building for service-oriented distributed set of processes Potencial to mesure the impact of service changes, and affected compositions that interact with these services 9/5/2015http://

Conclusions It is important to compose the service workflow correctly for all the services actors Verify the flow before actual implementation and deployment is undertaken Verify compensation routines between processes 9/5/2015http://

The end... 9/5/2015http://