Top-down business process development and execution using quality of service aspects

This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Developing cross-organisational business processes is a challenging task. The partners have to agree on a common data format and meaning as well as on the quality of service (QoS) requirements each partner has to fulfil. The QoS requirements are typically described using service level agreements (SLAs) among the partners. In this paper, a top-down modelling approach for Web service based business processes is proposed to capture the functional and non-functional aspects using a choreography language (WS-CDL) which describes the message interactions among the participants. The choreography is annotated with SLAs for the different partners. For each partner in the process, an orchestration (in WS-BPEL) and the necessary Web service templates are automatically generated. The service level objectives (SLOs) from the partner SLAs are automatically translated into policies that can then be enforced by a BPEL engine during execution. The deployment of the WSDL files, the monitoring of QoS attributes and the execution of the BPEL process itself are then handled by the VRESCo SOA runtime. 1. Introduction Service-oriented architecture (SOA) represents an emerging paradigm to develop flexible and large-scale software systems using the Internet as the main infrastructure. Web services are one realisation of this paradigm by using well-established standards to describe and interact with other services.