Reasoning About a Service-oriented Programming Paradigm

This paper is about a new way for programming distributed applications: the service-oriented one. It is a concept paper based upon our experience in developing a theory and a language for programming services. Both the theoretical formalization and the language interpreter showed us the evidence that a new programming paradigm exists. In this paper we illustrate the basic features it is characterized by

Requirements-Driven Adaptation of Choreographed Interactions

Electronic services are emerging as the de-facto enabler of interaction interoperability across organization boundaries. Cross-organizational interactions are often “choreographed”, i.e. specified by a messaging protocol from a global point of view independent of the local view of each interacting organization. Local requirements motivating an interaction as well as the global contextual requirements governing the interaction inevitably evolve over time, requiring adaptation of the corresponding interaction protocol. Adaptation of an interaction protocol must ensure the satisfaction of both sets of interaction requirements while maintaining consistency between the global view and the local views of an interaction specification. Such adaptation is not possible with the current state-of-the-art representations of choreographed interactions, as they capture only operational messaging specifications detached from both local organizational requirements as well as global contextual requirements. This thesis presents three novel contributions that tackle adaptation of choreographed interaction protocols: an automated technique for deriving an interaction protocol from requirements, a formalization of consistency between local and global views, and a framework for guiding the adaptation of a choreographed interaction. A choreographed interaction is specified using models of organizational requirements motivating the interaction. We employ the formal semantics embedded in requirements models to automatically derive an interaction protocol. We propose a framework for relating the global and local views of interaction specification and maintaining consistency between them. We develop a metamodel for interaction specification, from which we enumerate adaptation operations. We build a catalogue that provides guidance on performing each operation and propagating changes between the global and local views. These contributions are evaluated using examples from the literature as well as a real-world case study

A Compositional Framework for Service Interaction Patterns and Interaction Flows

Abstract. We provide precise high-level models for eight fundamental service interaction patterns, together with schemes for their composition into complex service-based business process interconnections and interaction flows, supporting software-engineered business process management in multi-party collaborative environments. The mathematical nature of our models provides a basis for a rigorous execution-platform-independent analysis, in particular for benchmarking web services functionality. The models can also serve as accurate standard specifications, subject to further design leading by stepwise refinement to implementations. We begin by defining succinct rigorous models to mathematically capture the behavioral meaning of four basic bilateral business process interaction patterns (Sect. 1), together with their refinements to four basic multilateral interaction patterns (Sect. 2). We then illustrate with characteristic examples how by appropriate combinations and refinements of these eight fundamental patterns one can define arbitrarily complex interaction patterns of distributed service-based business processes that go beyond simple request-response sequences and may involve a dynamically evolving number of participants. This leads to a definition of the concept of process interaction flow or conversation