On Evolving Partitioned Web Service Orchestrations

International audienceMany researches argue that centralized Web Service (WS) orchestrations stop short in dealing with key requirements such as scalability, privacy and reliability. Consequently, fragmentation and decentralization have been proposed to overcome these limitations. In detail, the centralized orchestration is fragmented into behaviorally equivalent distributed partitions such that their combined execution recreates the function of the original orchestration. However, the evolving nature of business processes as well as the necessity to adapt to market changes created the need for an efficient change support. Since the decentralization leads to the distribution of the activities, the control and data flows, it becomes difficult to specify the changes directly on the derived partitions. Therefore, it is more judicious to specify the changes on the centralized orchestration model and propagate the changes to the derived partitions. In this paper, we propose a comprehensive change framework for partitioned WS orchestration scenarios and demonstrate how to specify and propagate the changes from the centralized model to its resulting decentralized partitions. The main advantage of such an approach is that only partitions that are related to the specified changes are affected. There is no need to re-compute the whole orchestration and re-deploy all the distributed partitions

Dealing with change in process choreographies: Design and implementation of propagation algorithms

Enabling process changes constitutes a major challenge for any process-aware information system. This not only holds for processes running within a single enterprise, but also for collaborative scenarios involving distributed and autonomous partners. In particular, if one partner adapts its private process, the change might affect the processes of the other partners as well. Accordingly, it might have to be propagated to concerned partners in a transitive way. A fundamental challenge in this context is to find ways of propagating the changes in a decentralized manner. Existing approaches are limited with respect to the change operations considered as well as their dependency on a particular process specification language. This paper presents a generic change propagation approach that is based on the Refined Process Structure Tree, i.e., the approach is independent of a specific process specification language. Further, it considers a comprehensive set of change patterns. For all these change patterns, it is shown that the provided change propagation algorithms preserve consistency and compatibility of the process choreography. Finally, a proof-of-concept prototype of a change propagation framework for process choreographies is presented. Overall, comprehensive change support in process choreographies will foster the implementation and operational support of agile collaborative process scenarios