Specifying Instance Correspondence in Collaborative Business Processes

In recent years, organisations have been undergoing a thorough transformation towards highly flexible and agile collaborations. Organisations are required to dynamically create and manage collaborative business processes to grasp market opportunities. Different from conventional business processes, a collaborative business process involves multiple parties and their business processes [1]. Thus, complex instance correspondences may exist at both build time and run time. Here, we choose to characterise instance correspondences in terms of cardinality and correlations. Thereby, we can define and represent statical and dynamic corresponddence when modelling and executing a collaborative business process. Multiple workflow instantiation was discussed by Dumas and ter Hofstede [2], using UML activity diagrams. Later they extended their work to service interactions [3]. van der Aalst et al. [4] deployed coloured Petri nets to represent multiple workflow cases in workflow patterns, and implemented it in the YAWL system [5]. Zhou, Shi and Ye [6] also studied pattern based modelling for multiple instances of workflow activities. Guabtni and Charoy [7] extended the multiple instantiation patterns and classified multiple workflow instantiation into parallel and iterative instances. Yet, most of these research focus on interaction patterns, and sidestep the instance correspondence issue in collaborative business processes. WS-BPEL (previously BPEL4WS) [8] uses its own correlation set to combine workflow instances, which have same values on specified message fields. However, WS-BPEL defines a business process in terms of a pivot organisation, which results in the lack of interactions beyond neighbouring organisations. Aiming to address the instance correspondence issue, we propose a method to support instance correspondences from an organisation-oriented view. In our method, cardinality parameters are developed to characterise cardinality relationships between collaborating workflow processes at build time. The four bilateral cardinality relationships, viz., singleto-single, single-to-many, many-to-single and many-to-many, are represented by a pair of unidirectional cardinality relationships, which can be either to-single or to-many. Thereby, the cardinality relationship between workflow processes participating in the same collaboration can be defined from the perspective of a given organisation. Workflow correlation denotes the semantic relation between workflow instances in the same business collaboration. Two or more workflow instances are directly correlated,