In Service Oriented Computing (SOC), different services interact and exchange information to reach specific objectives. To model interorganizational SOC systems, choreography modeling languages have emerged to represent the distributed coordination among the involved organizations. From the realization perspective, blockchain technology is emerging as a promising run-time supporting peer-to-peer communication technology without the need for a central coordinator, thanks to its intrinsic security, trust, and decentralization characteristics. However, while blockchain can bring many advantages, technological barriers still limit its adoption in organizations, due to the costly and time-consuming learning process. For this reason, we propose RESTChain, a framework that automatically enables the interactions that take place among the participants in a service choreography exploiting blockchain technology. Starting from a choreography specification, the framework provides a set of mediators and automatically generates a smart contract that coordinates the service interactions. The mediators are software components that are directly connected with the smart contracts and expose REpresentational State Transfer (REST) APIs in compliance with the role played by the organizations in the choreography. In this way, the services deployed by one organization can communicate with the services made available by another organization through the blockchain in a secure and transparent manner. The proposed approach has been implemented on the Layer 2 Polygon blockchain and validated in a market retail case study analyzing its efficiency in terms of time and cost.

The recent growth of blockchain has opened the use of technology for supporting the creation of newkinds of trustable systems. Model-driven engineering methodologies have been conceived to facilitate the automatic generation and deployment of software applications starting from the definition and refinement of abstract specification. BPMN choreography diagrams permit the representation of inter-organisational systems from a high-level perspective, just focusing on message exchange. However, the usage of such models in a blockchain-based setting has been limited to scenarios in which parties are involved in single interactions. This aspect becomes significantly relevant when considering complex applications, particularly those in the realm of the Internet of Things. In these cases, the multiplicity of parties and their actions is crucial and requires novel solutions. In this work, we propose a novel approach for modelling, refining, deploying, and executing a choreography on the blockchain, taking into account those scenarios in which the model includes multiple instances. In particular, the considered models are translated into smart contracts able to correctly manage multiplicity. To demonstrate the approach’s feasibility, we designed and presented a smart thermostat application, which is executed on the Polygon blockchain.

Voluntary Geographic Information initiatives are transforming the disaster response landscape. Our research provides insights into how the concept of collective intelligence is accomplished in humanitarian mapping initiatives. The main source originates from the data obtained in 746 mapping projects organised by the Humanitarian OpenStreetMap Team between December 2021 and November 2023, where 38,893 contributors completed 312,289 mapping tasks. These data include detailed attributes of the contributors and the states the tasks go through. The methodology adopts a quantitative approach, including descriptive and inferential statistics, and standard process mining techniques. Our results indicate that, in general terms, in humanitarian mapping, a group of contributors from outside the area of interest perform straightforward mapping tasks with limited collaboration among them. The ‘wisdom’ of advanced contributors is the cornerstone that sustains the system. The discussion section elaborates on (1) how these findings suggest that humanitarian mapping projects effectively meet their short-term mapping objectives but fall short if more sustainable mapping objectives are sought and (2) possible strategies for better harnessing the collective intelligence of these efforts.

Blockchain technology is increasingly adopted in scenarios requiring trust and data integrity. On the Ethereum blockchain, the proxy pattern has become increasingly popular because it allows smart contract code to evolve while preserving stored data. However, a key challenge remains ensuring that such upgrades do not introduce breaking changes or cause disruptions to other contracts and off-chain systems. In this article, we introduce Catana , a framework that leverages historical transactions for Capture-Replay testing of proxy-based Upgradeable Smart Contracts (USCs). Catana assesses the potential impact of an upgrade by comparing the outcomes of replayed transactions with those from the previous version deployed on the main network. Additionally, it extracts and decodes contract state variables, providing deeper insights into how code changes affect the contract state, and helping developers mitigate issues before deployment. Experiments demonstrate that analyzing storage data accounts for the majority (about 86.5%) of detected disruptive upgrades. We also evaluate different policies for building replay test suites from historical transactions. Results identify a strategy that maximizes effectiveness while requiring a small number of replay test executions. Even a test suite containing just one transaction per each invoked method achieved good effectiveness (about 60%) in detecting disruptive upgrades.

Smart contracts hold the potential to revolutionize various industries, but their implementation requires thorough testing due to the associated financial risks. Mutation testing is a powerful technique that can boost the fault-detection capabilities of a test suite, but it can also foster a deeper understanding of smart contract behavior. This work investigates the productivity of mutants with respect to their capabilities in disclosing Solidity issues. Based on these findings, it proposes an enhanced mutation strategy to better assist smart contract auditors during code inspection activities. 9 novel mutation operators are introduced in this paper and 13 existing operators are improved. The results show a $30 \%$ reduction in the number of generated mutants and time savings of $62 \%$, while increasing the set of productive mutants related to issues by $43 \%$ overall. We note that the most valuable type of mutants that could help disclose an issue as a result of manual mutant inspection was increased by $125 \%$.

Abstract The capability to integrate Internet of Things (IoT) technologies into business processes (BPs) has emerged as a transformative paradigm, offering unprecedented opportunities for organisations to enhance their operational efficiency and productivity. Interacting with the physical world and leveraging real-world data to make more informed business decisions is of greatest interest, and the idea of IoT-enhanced BPs promises to automate and improve business activities and permit them to adapt to the physical environment of execution. Nonetheless, combining these two domains is challenging, and it requires new modelling methods that do not increase notation complexity and provide independent execution between the process and the underlying device technology. In this work, we propose FloBP, a model-driven engineering approach separating concerns between the IoT and BPs, providing a structured and systematic approach to modelling and executing IoT-enhanced BPs. Applying the separation of concerns through an interdisciplinary team is needed to ensure that the approach covers all necessary process aspects, including technological and modelling ones. The FloBP approach is based on modelling tools and a microservices architecture to deploy BPMN models, and it facilitates integration with the physical world, providing flexibility to support multiple IoT device technologies and their evolution. A smart canteen scenario describes and evaluates the approach’s feasibility and its possible adoption by various stakeholders. The performed evaluation concludes that the application of FloBP facilitates the modelling and development of IoT-enhanced BPs by sharing and reusing knowledge among IoT and BP experts.

In modern business scenarios, more and more organisations have to deal with the critical requirements of trustworthiness and flexibility, when collaborating in multi-party business processes. This calls for new kinds of systems able to manage collaborative processes in untrusted and dynamic environments. Concerning the collaborative perspective, the Business Process Management discipline has provided effective and standardised solutions for a long time, now. Regarding the trustworthiness perspective, blockchain is advocated as one of the most prominent technologies to guarantee trust in a multi-party setting. However, while the immutability of blockchain provides transparent and secure proof of past business interactions, it hinders the flexibility of the business process execution, as the business logic regulating the process execution is immutably stored in the blockchain. On the other hand, flexibility is a property that is becoming crucial in such a setting due to the high dynamism of the business scenarios. In fact, it permits to modify a process at run-time to deal with internal or external changes. In this paper, we face this issue by proposing an architecture for the flexible blockchain-based execution of multi-party business processes. In our approach, business processes are modelled by BPMN choreography diagrams translated into code, whose execution state is then stored in the blockchain. Flexibility is achieved by decoupling the business process’s logic from its execution state, thus allowing run-time changes to the process execution without losing the fundamental properties of trust provided by the blockchain. To show the effectiveness of our approach, we provide a prototypical implementation, called FlexChain, and we use it on a case study from the healthcare application domain. The results obtained by the analysis of cost for the reported case study show the feasibility of the approach. In particular, major costs to sustain relate to one-time operations, such as the deployment and the run-time update of the model, while the most frequent actions are quite efficient.

Smart Contracts are software programs that are deployed and executed within a blockchain infrastructure. Due to their immutable nature, directly resulting from the specific characteristics of the deploying infrastructure, smart contracts must be thoroughly tested before their release. Testing is one of the main activities that can help to improve the reliability of a smart contract, so as to possibly prevent considerable loss of valuable assets. It is therefore important to provide the testers with tools that permit them to assess the activity they performed.Mutation testing is a powerful approach for assessing the fault-detection capability of a test suite. In this paper, we propose SuMo, a novel mutation testing tool for Ethereum Smart Contracts. SuMo implements a set of 44 mutation operators that were designed starting from the latest Solidity documentation, and from well-known mutation testing tools. These allow to simulate a wide variety of faults that can be made by smart contract developers. The set of operators was designed to limit the generation of stillborn mutants, which slow down the mutation testing process and limit the usability of the tool. We report a first evaluation of SuMo on open-source projects for which test suites were available. The results we got are encouraging, and they suggest that SuMo can effectively help developers to deliver more reliable smart contracts.

As a disruptive technology, the blockchain is continuously finding novel application contexts, bringing new opportunities and radical changes. In this paper, we use blockchain as a communication infrastructure to support multi-party business processes. In particular, through smart contracts specifically generated by the mentioned business process, it is possible to derive a trustable infrastructure enabling the interaction among parties. Moreover, the emergence of different blockchain technologies, satisfying different characteristics, gives the possibility to support the same business process dealing with different non-functional needs. In this paper, we propose a novel engineering methodology supported by a practical framework called Multi-Chain. It permits to derive, using a model-driven strategy, a blockchain-based infrastructure, that can be deployed over a specific blockchain technology (e.g., Ethereum or Hyperledger Fabric). The objective is to permit the single definition and multiple deployments of the business process, to deliver the same functionalities, but satisfying different non-functional needs. In such a way, organisations willing to cooperate can select the multi-party business process and the blockchain technology they would like to use to satisfy their needs. Using Multi-Chain, they will be able to automatically derive from a Business Process Modelling Notation (BPMN) choreography diagram a blockchain infrastructure ready to be used. This overcomes the need to get acquainted with many details of the specific technology.

The BPMN 2.0 standard is nowadays largely used to model distributed informative systems in both academic and industrial contexts. The notation makes possible to represent these systems from different perspectives. A local perspective, using collaboration diagrams, to describe the internal behaviour of each component of the systems, and a global perspective, using choreography diagrams, where the interactions between system components are highlighted without exposing their internal structure. In this paper, we propose a formal approach for checking conformance of collaborations, representing possible system implementations, with respect to choreographies, representing global constraints concerning components' interactions. In particular, we provide a direct formal operational semantics for both BPMN collaboration and choreography diagrams, and we formalise the conformance concept by means of two relations defined on top of the semantics. To support the approach into practice we have developed the C 4 tool. Its main characteristic is to make the exploited formal methods transparent to systems designers, thus fostering a wider adoption of them in the development of distributed informative systems. We illustrate the benefits of our approach by means of a simple, yet realistic, example concerning a traveling scenario.

Summary European Union (EU) projects are means of the European Commission for funding research activities. Such projects address challenging research objectives by involving both academic and industrial partners, from several countries. Information and communication technologies–related projects often undertake to deliver a software system prototype. In such a context, most of the typical issues of global requirements engineering may emerge. Partners can have different background and expertise, needs are not sharply defined, and communication is hampered by linguistic and cultural differences. If these issues are not carefully taken into account from the beginning, problems frequently emerge during project execution. This paper presents the experience of applying a customized elicitation and refinement approach in the context of the Learn PAd EU project, which involved about 50 people. The approach combines collaborative elicitation and wiki‐based refinement sessions to come to a set of consolidated requirements. Lessons learnt are discussed as a guidance for researchers dealing with analogous issues in similar contexts. Some of the major observations refer to the importance of initial face‐to‐face meetings when combined with asynchronous remote interactions; the role of moderators that have to encourage collaboration and foster a shared understanding; and the definition of guidelines to select wiki‐based platforms.

Business Process Modelling has acquired increasing relevance in software development. Available notations, such as BPMN, permit to describe activities of complex organisations. On the one hand, this shortens the communication gap between domain experts and IT specialists. On the other hand, this permits to clarify the characteristics of software systems introduced to provide automatic support for such activities. Nevertheless, the lack of formal semantics hinders the automatic verification of relevant properties. This paper presents a novel verification framework for BPMN 2.0, called BProVe. It is based on an operational semantics, implemented using MAUDE, devised to make the verification general and effective. A complete tool chain, based on the Eclipse modelling environment, allows for rigorous modelling and analysis of Business Processes. The approach has been validated using more than one thousand models available on a publicly accessible repository. Besides showing the performance of BProVe, this validation demonstrates its practical benefits in identifying correctness issues in real models.

This demo introduces BProVe, a tool supporting automated verification of Business Process models. BProVe analysis is based on a formal operational semantics defined for the BPMN 2.0 modelling language, and is provided as a freely accessible service that uses open standard formats as input data. Furthermore a plug-in for the Eclipse platform has been developed making available a tool chain supporting users in modelling and visualising, in a friendly manner, the results of the verification. Finally we have conducted a validation through more than one thousand models, showing the effectiveness of our verification tool in practice. (Demo video: https://youtu.be/iF5OM7vKtDA).

Multitenancy is one the new property of cloud computing paradigm that change the way of develop software. This concept consists in the aggregation of different tenant in one single istance in contrast with the classic single-tenant concept. The aim of multitenancy is the reduction of costs, the hardware needed is less than single-tenant application, and also the mantainance of the system is less expensive. On the other hand, applications need an high configuration level in order to satisfy the requirements of each tenant. In this paper is presented a pattern that enable legacy applications to handle a multitenancy database. After the presentation of the different approach that implements multitenancy at database system, it is proposed the pattern that aims to interact with this kind of database managing the different customization of different tenant at database level. Copyright © 2016 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved.

Applications and services hosted in the cloud are increasing continuously. Cloud technology offers important perspectives (performance, high availability, elasticity) and it enables new business models. Unfortunately, this new paradigm faces unprecedent requirements not addressed in legacy application (multi-tenancy, scalability, etc.). This leads to complex re-engineering phases in order to to migrate existing software into a cloud environment. Before starting a migration, it is important to analyze the cloud compliance of the application, what to expect after the migration and the effort required to fulfill these expectations. This paper assesses a way to extract an index that describes the feasibility of the re-engineering. We test the metric with a real application that needs to be migrated to a private cloud.

A Service Oriented Architecture aims to facilitate interaction of loosely coupled services in large-scale dynamic systems. Despite a decade’s active research and development, Web Services still remain undependable (Bourne et al., 2012). In literature many proposals attempt to overcome interoperability issues, particularly typical of not-orchestrated Web Service (WS) compositions. Although these techniques aid to discover potential interoperability mismatches, they do not fit well with flexibility and dynamism, desirable characteristics e.g. in choreographies. Here unsafe run-time changes may compromise a correct execution. To support such dynamism and to mitigate the effects of such failures, we propose a flexible architecture able to realize dynamic WS compositions, supporting run-time monitoring and verification techniques. The technique we chose is a novel run-time algorithm capable to predict potential failures that can happen in near future states of a choreography. It a dmits an integration ”a-priori” and monitors the run-time services behaviour to provide information about possible errors when these can happen.

In run-time evolving systems, components may evolve while the system is being operated. Unsafe run-time changes may compromise the correct execution of the entire system. Traditional design-time verification techniques difficultly cope with run-time changes, and run-time monitoring may detect disfunctions only too late, when the failure arises. The desire would be to define advanced monitors with the ability to predict and prevent the potential errors happening in the future. In this direction, this paper proposes CASSANDRA, a new approach that by combining design-time and run-time analysis techniques, can “look ahead” in the near execution future, and predict potential failures. During run-time we on-the-fly construct a model of the future k-step global state space according to design-time specifications and the current execution state. Consequently, we can run-time check whether possible failures might happen in the future.

This paper summarizes the workshop on Architecture-Based Testing and System Validation which was organized in conjunction with the 9th Working IEEE/IFIP Conference on Software Architecture. The main goal of the workshop was to bring together researchers and practitioners both from the architecture design and software testing community to enable architecture-based software testing.

Service oriented computing is based on a typical combination of features such as very late binding, run-time integration of software elements owned and managed by third parties, run-time changes. These characteristics generally make difficult both static and dynamic verification capabilities of service-centric systems. In this domain verification and testing research communities have to face new issues and revise existing solutions; possibly profiting of the new opportunities that the new paradigm makes available. In this paper, focusing on service orchestrations, we propose an approach to automatic test case generation aiming in particular at checking the behaviour of services participating in a given orchestration. The approach exploits the availability of a runnable model (the BPEL specification) and uses model checking techniques to derive test cases suitable to detect possible integration problems. The approach has been implemented in a plug-in for the Eclipse platform already released for public usage. In this way BPEL developers can easily derive, using a single environment, test suites for each participant service they would like to compose.

Web services (WSs) are the W3C-endorsed realization of the Service-Oriented Architecture (SOA). Since they are supposed to be implementation-neutral, WSs are typically tested black-box at their interface. Such an interface is generally specified in an XML-based notation called the WS Description Language (WSDL). Conceptually, these WSDL documents are eligible for fully automated WS test generation using syntax-based testing approaches. Towards such goal, we introduce the WS-TAXI framework, in which we combine the coverage of WS operations with data-driven test generation. In this paper we present an early-stage implementation of WS-TAXI, obtained by the integration of two existing softwares: soapUI, a popular tool for WS testing, and TAXI, an application we have previously developed for the automated derivation of XML instances from a XML schema. WS-TAXI delivers a complete suite of test messages ready for execution. Test generation is driven by basic coverage criteria and by the application of some heuristics. The application of WS-TAXI to a real case study gave encouraging results.

Provides notice of upcoming conference events of interest to practitioners and researchers.

Software engineering practitioners and researchers continue to face huge challenges in the development, maintenance, and use of software systems. This has been even more prominent with the new paradigm of service oriented computing in which service integrators, developers, and providers need to create methods, tools, and techniques to support cost-effective development and use of dependable services and service oriented applications. This workshop provides a forum for presentations and discussions of topics related to service oriented software engineering paradigm.

Abstract Component‐based development has emerged as a system engineering approach that promises rapid software development with fewer resources. Yet, improved reuse and reduced cost benefits from software components can only be achieved in practice if the components provide reliable services, thereby rendering component analysis and testing a key activity. This paper discusses various issues that can arise in component testing by the component user at the stage of its integration within the target system. The crucial problem is the lack of information for analysis and testing of externally developed components. Several testing techniques for component integration have recently been proposed. These techniques are surveyed here and classified according to a proposed set of relevant attributes. The paper thus provides a comprehensive overview which can be useful as introductory reading for newcomers in this research field, as well as to stimulate further investigation. Copyright © 2006 John Wiley & Sons, Ltd.

No abstract available.

Component-based development is the emerging paradigm in software production, though several challenges still slow down its full taking up. In particular, the "component trust problem" refers to how adequate guarantees and documentation about a component's behaviour can be transferred from the component developer to its potential users. The capability to test a component when deployed within the target application environment can help establish the compliance of a candidate component to the customer's expectations and certainly contributes to "increase trust". To this purpose, we propose the CDT framework for Component Deployment Testing. CDT provides the customer with both a technique to early specify a deployment test suite and an environment for running and reusing the specified tests on any component implementation. The framework can also be used to deliver the component developer's test suite and to later re-execute it. The central feature of CDT is the complete decoupling between the specification of the tests and the component implementation.