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TopIntroduction And Problem Statement
Business processes constitute the cornerstone of modern organizations. Thus, companies invest huge efforts and sums for managing the associated life cycles while modeling and maintaining their processes schemes. Meanwhile, as a revolutionary technique in the software industry, Web services are becoming the new generation of software components allowing the implementation of various kinds of business processes. In fact, Web services technology is suitable for supporting the integration of distributed and heterogeneous information systems.
Two elements are fundamental to enhancing the interactivity level between the different stakeholders involved in Web services environments. First, the service interface describes static elements useful for invoking the available operations, like messages, types, port types, and the required protocol. However, as service operations cannot be invoked in an aleatory fashion, the service protocol represents an abstract tool to specify the operations sequences imposed by the service provider according to his business logic. In a nutshell, a service protocol is an abstract model which handles the sequence of messages that a service and its clients exchange to achieve a certain business goal (Alonso et al., 2004; Ryu et al., 2008; Benatallah et al., 2006). In this perspective, the research literature has highlighted the usefulness of service protocols, and various models performing different expressivity and relevance levels have been suggested to handle different types of constraints.
Nowadays, contemporary enterprises evolve in a turbulent environment from which they recover information related to customer needs, partners, and competitors, and for which they produce consumer goods for clients and other companies. Indeed, due to the phenomenon of economic globalization and as a consequence of advances in information and communication technology (ICT), the market has become global, and competition is increasingly hard. Consequently, enterprises must face a high level of dynamicity where evolutions become intrinsic aspects of such competitive environments. The development of modern corporations leads to their transformation into open systems that have close connections with a highly unexpected and unstable environment; in return, their survival is dependent on them. Many reasons, such as changes in the business logic or business strategies, the evolution of laws and regulations, and adaption needs, can lead to changes in the already deployed Web services specifications. Business protocol evolution involves updating an old protocol description, e.g., adding or removing activities or steps in the current procedure to comply with new business requirements (Khebizi et al., 2017). In this context, a crucial issue lies in the management of active instances having started their interactions based on the old service protocol version. In fact, stopping a system while execution instances are still running may involve a loss of historical work that has been accomplished. Therefore, the ability to ensure the system's continuation without stopping it should be an option. However, the problem is the management of the ongoing instances having started according to the previous protocol when it has been modified. To address such issues, a thorough analysis of active instances that need to comply with the business modifications is required. Hence, defining a seamless migration strategy must focus on two complementary aspects: the business protocol specification and the progression level of instances to be migrated to the new protocol (Khebizi et al., 2017). Ryu et al. (2008) proposed three migration strategies: continuation, migration to the new protocol, and migration to ad hoc protocol. Figure 1 illustrates the scenario of business protocol evolution and its challenging issues.