Annapaola Marconi

Automated synthesis of composite BPEL4WS Web services

In this paper we propose a technique for the automated synthesis of new composite Web services. Given a set of abstract BPEL4WS descriptions of component services, and a composition requirement, we automatically generate an executable BPEL4WS process that, once deployed, is able to interact with the components to satisfy the requirement. We implement the proposed approach exploiting efficient synthesis techniques, and experiment with some case studies taken from real world applications and with a parameterized domain. We show that the technique can scale up to cases in, which the manual development of BPEL4WS composite services is not trivial and is time consuming.

Synthesis and Composition of Web Services

One of the key ideas underlying Web services is that of allowing the combination of existing services published on the Web into a new service that achieves some higher-level functionality and satisfies some business goals. As the manual development of the new composite service is recognized as a difficult and error-prone task, the automated synthesis of the composition is considered one of the key challenges in the field of Web services. In this paper, we will present a survey of existing approaches for the synthesis of Web service compositions. We will then focus on a specific approach, the ASTRO approach, which has been shown to support complex composition requirements and to be applicable in real domains. In the paper, we will present the formal framework behind the ASTRO approach; we will present the implementation of the framework and its integration within a commercial toolkit for developing Web services; we will finally evaluate the approach on a real-world composition domain.

Dynamic Adaptation of Fragment-Based and Context-Aware Business Processes

We propose a comprehensive framework for adaptivity of service-based applications, which exploits the concept of process fragments as a way to model reusable process knowledge and to allow for the dynamic, incremental, context-aware composition of such fragments into adaptable service-based applications. The framework provides a set of adaptation mechanisms that, combined through adaptation strategies, are able to solve complex adaptation problems. An implementation of the proposed solution is presented and evaluated on a real world scenario from the logistics domain.

Multi-layered monitoring and adaptation

Service-based applications have become more and more multi-layered in nature, as we tend to build software as a service on top of infrastructure as a service. Most existing SOA monitoring and adaptation techniques address layer-specific issues. These techniques, if used in isolation, cannot deal with real-world domains, where changes in one layer often affect other layers, and information from multiple layers is essential in truly understanding problems and in developing comprehensive solutions. In this paper we propose a framework that integrates layer specific monitoring and adaptation techniques, and enables multi-layered control loops in service-based systems. The proposed approach is evaluated on a medical imaging procedure for Computed Tomography (CT) Scans, an e-Health scenario characterized by strong dependencies between the software layer and infrastructural resources.

Enabling Adaptation of Pervasive Flows: Built-in Contextual Adaptation

Adaptable pervasive flows are dynamic workflows situated in the real world that modify their execution in order to adapt to changes in the execution environment. This requires on the one hand that a flow must be context-aware and on the other hand that it must be flexible enough to allow an easy and continuous adaptation. In this paper we propose a set of constructs and principles for embedding the adaptation logic within the specification of a flow. Moreover, we show how a standard language for web process modeling (BPEL) can be extended to support the proposed built-in adaptation constructs.

Implicit vs. explicit data-flow requirements in web service composition goals

In this paper we compare two different approaches to specify data-flow requirements in Web service composition problems, i.e., requirements on data that are exchanged among component services. Implicit data-flow requirements are a set of rules that specify how the functions computed by the component services are to be combined by the composite service. They implicitly define the required constraints among exchanged data. Explicit data-flow requirements are a set of explicit specifications on how the composition should manipulate messages and route them from/to components. In the paper, we compare these two approaches through an experimental evaluation, both from the point of view of efficiency and scalability and from that of practical usability.

Dynamic Composition of Pervasive Process Fragments

A critical aspect for pervasive computing is the possibility to discover and use process knowledge at run time depending on the specific context. This can be achieved by using an underlying service-based application and exploiting its features in terms of dynamic service discovery, selection, and composition. Pervasive process fragments represent a service-based tool that allows to model incomplete and contextual knowledge. We provide a solution to automatically compose such fragments into complete processes, according to a specific context and specific goals. We compute the solution by encoding process knowledge, domain knowledge and goals into an AI planning problem. We evaluate our approach on different scenarios stress testing the main characteristics of pervasive process fragments.

A formalisation of adaptable pervasive flows

Adaptable Pervasive Flows is a novel workflow-based paradigm for the design and execution of pervasive applications, where dynamic workflows situated in the real world are able to modify their execution in order to adapt to changes in their environment. In this paper, we study a formalisation of such flows by means of a formal flow language. More precisely, we define APFoL (Adaptable Pervasive Flow Language) and formalise its textual notation by encoding it in Blite, a formalisation of WS-BPEL. The encoding in Blite equips the language with a formal semantics and enables the use of automated verification techniques. We illustrate the approach with an example of a Warehouse Case Study.

Automated synthesis of executable web service compositions from BPEL4WS processes

We propose a technique for the automated synthesis of new composite web services. Given a set of abstract bpel4ws descriptions of component services, and a composition requirement, we automatically generate a concrete bpel4ws process that, when executed, interacts with the components and satisfies the requirement.We implement the proposed approach exploiting efficient representation techniques, and we show its scalability over case studies taken from a real world application and over a parameterized domain.

Using gamification to incentivize sustainable urban mobility

Sustainable urban mobility is an important dimension in a Smart City, and one of the key issues for city sustainability. However, innovative and often costly mobility policies and solutions introduced by cities are liable to fail, if not combined with initiatives aimed at increasing the awareness of citizens, and promoting their behavioural change. This paper explores the potential of gamification mechanisms to incentivize voluntary behavioural changes towards sustainable mobility solutions. We present a service-based gamification framework, developed within the STREETLIFE EU Project, which can be used to develop games on top of existing services and systems within a Smart City, and discuss the empirical findings of an experiment conducted in the city of Rovereto on the effectiveness of gamification to promote sustainable urban mobility.