Caterpillar: A business process execution engine on the Ethereum blockchain

Blockchain platforms, such as Ethereum, allow a set of actors to maintain a ledger of transactions without relying on a central authority and to deploy programs, called smart contracts, that are executed whenever certain transactions occur. These features can be used as basic building blocks for executing collaborative business processes between mutually untrusting parties. However, implementing business processes using the low-level primitives provided by blockchain platforms is cumbersome and error-prone. In contrast, established business process management systems (BPMSs), such as those based on the standard Business Process Model and Notation (BPMN), provide convenient abstractions for rapid development of process-oriented applications. This article demonstrates how to combine the advantages of a BPMS with those of a blockchain platform. The article introduces a blockchain-based BPMN execution engine, named Caterpillar. Like any BPMN execution engine, Caterpillar supports the creation of instances of a process model and allows users to monitor the state of process instances and to execute tasks thereof. The specificity of Caterpillar is that the state of each process instance is maintained on the (Ethereum) blockchain and the workflow routing is performed by smart contracts generated by a BPMN-to-Solidity compiler. The Caterpillar compiler supports a large array of BPMN constructs, including subprocesses, multiple-instance activities, and event handlers. The paper describes the architecture of Caterpillar and the interfaces it provides to support the monitoring of process instances, the allocation and execution of work items, and the execution of service tasks.     

Dynamic execution planning for reliable collaborative business processes

Collaborative business processes, implemented and carried out via web services and enabling dynamic interaction among organizations, are becoming more indispensable to competitiveness in the global market. As dynamic collaboration prevails, the quality of service (QoS) of collaborative processes becomes more important. A critical requirement in cases where processes involve long-term activities is to guarantee successful completion within time constraints. In this study, we developed a methodology for dynamic planning of web service execution that imparts reliability to collaborative business processes. In order to ensure that processes successfully execute within time constraints and at minimum cost, the proposed method dynamically modifies execution plans at run-time by means of fault-tolerance techniques. Since generation of an execution plan of minimum cost while guaranteeing successful completion is classified as an NP-hard problem, a heuristic algorithm was developed. Additionally, to compare the proposed algorithm’s performance with those of the branch-and-bound method and the genetic algorithm (GA), a set of experiments was conducted.     

Distributed process execution in collaborative networks

Processes are a central entity in enterprise collaboration. Collaborative processes need to be executed and coordinated in a distributed computational platform where computers are connected through heterogeneous networks and systems. Life cycle management of such collaborative processes requires a framework able to handle their diversity based on different computational and communication requirements. This paper proposes a rational for such framework, points out key requirements and proposes a strategy for a supporting technological infrastructure. Beyond the portability of collaborative process definitions among different technological bindings, a framework to handle different life cycle phases of those definitions is presented and discussed.     

多主体业务流程的可靠执行模型

当前工作流管理中,业务流程执行的可靠性是一个不容忽视的重要问题,然而,现有的研究在解决多主体协调并发执行过程中的主体夭折问题存在不足。基于迁移工作流模型,提出一种多迁移实例的可靠执行模型,模型可以实现不同层次上的执行主体监测与故障诊断和处理;同时设计守护实例具有可移动、可复制以及自动退出等特点,有效提高了检测准确性和监控效率。实验表明,模型具有高可靠性和低开销以及可扩展性等技术优势,特别适合当前跨机构环境中多主体的并发执行。     

On the adoption of blockchain for business process monitoring

Being the blockchain and distributed ledger technologies particularly suitable to create trusted environments where participants do not trust each other, business process management represents a proper setting in which these technologies can be adopted. In this direction, current research work primarily focuses on blockchain-oriented business process design, or on execution engines able to enact processes through smart contracts. Conversely, less attention has been paid to study if and how blockchains can be beneficial to business process monitoring. This work aims to fill this gap by (1) providing a reference architecture for enabling the adoption of blockchain technologies in business process monitoring solutions, (2) defining a set of relevant research challenges derived from this adoption, and (3) discussing the current approaches to address the aforementioned challenges.

     

Context aware exception handling in business process execution language

ContextFault handling represents a very important aspect of business process functioning. However, fault handling has thus far been solved statically, requiring the definition of fault handlers and handling logic to be defined at design time, which requires a great deal of effort, is error-prone and relatively difficult to maintain and extend. It is sometimes even impossible to define all fault handlers at design time.ObjectiveTo address this issue, we describe a novel context-aware architecture for fault handling in executable business process, which enables dynamic fault handling during business process execution.MethodWe performed analysis of existing fault handling disadvantages of WS-BPEL. We designed the artifact which complements existing statically defined fault handling in such a way that faults can be defined dynamically during business process run-time. We evaluated the artifact with analysis of system performance and performed a comparison against a set of well known workflow exception handling patterns.ResultsWe designed an artifact, that comprises an Observer component, Exception Handler Bus, Exception Knowledge Base and Solution Repository. A system performance analysis shows a significantly decreased repair time with the use of context aware activities. We proved that the designed artifact extends the range of supported workflow exception handling patterns.ConclusionThe artifact presented in this research considerably improves static fault handling, as it enables the dynamic fault resolution of semantically similar faults with continuous enhancement of fault handling in run-time. It also results in broader support of workflow exception handling patterns.     

An ontology-based collaborative business service selection: contributing to automatic building of collaborative business process

With worldwide inter-enterprise collaboration and interoperability background, automatic collaborative business process deduction is a crucial researching subject. We have designed a methodology of deducing collaborative process by only collecting collaborative objectives and partners’ business services. The two key problems are (i) selecting corresponding business services for a set of collaborative objectives and (ii) ordering business services with serializations and parallelization. This paper aims to present a solution of business service selection and the following business process extraction. In order to solve the problem, we have defined a collaborative ontology, which contains numerous instances of business services and processes from the MIT process handbook. The collaborative ontology contains essential concepts in collaborative situations and process-deducing rules and algorithms. We provide a brief illustration of implementation within a SaaS toolkit called Mediator Modeling 2ool.     

面向业务协作的本体协同编辑系统

为提高本体编辑工具的群体协作支持功能,发挥本体编辑必需的群体智慧作用,针对当前本体编辑工具不能较好满足协同性需求的实际情况,将网格的技术理念应用到本体编辑系统的构建之中,提出基于资源动态集成与协同交互技术的网格化虚拟协同本体编辑系统,并介绍了系统的体系结构与关键技术.     

Incorporating structural improvement into resource allocation for business process execution planning

Resource management has been recognised as an important topic for business process execution for a long time. Most existing works on resource allocation for business processes simply assume that the structure of a business process is always fixed, and therefore do not discuss the possibility of optimising resource allocation by adapting process structures to actual resource situations. To fill this gap, we propose a resource optimisation approach of improving process structures according to resource situations and thereby pursuing the best resource utilisation efficiency. This approach comprises a role‐based business process model for resource allocation and the strategies for optimising resource allocation in conjunction with a business process improvement. A set of heuristic rules are established to guide the resource allocation for the purposes of preventing resource conflicts, shortening the total execution time, minimising the total cost, etc. Particular algorithms are also developed to implement the resource allocation according to these rules. In addition, an experimental study is conducted to discuss the incorporation of business process improvement into resource allocation for optimal process execution. Copyright © 2012 John Wiley & Sons, Ltd.     

数据驱动的业务执行过程中人员行为差异性研究

为了研究业务执行过程中人员个体差异性和人员之间协作差异性,利用几个事件日志中记录的实际数据进行统计分析,了解了业务执行过程中人员的一些行为特征。分析结果表明：人员个体在业务过程中执行任务的种类,不同人员执行相同任务时的效率,人员在一个业务过程中的负荷,人员执行任务的偏好性,人员之间协作偏好性和人员之间协作效率存在差异性。掌握人员行为差异性能为业务执行过程中人员的合理配置提供了理论依据和数据支持。     

BPEL4WS协议中数据共享问题的研究

针对BPEL4WS协议在流程执行中数据共享问题处理上的不足,对协议的内容进行了拓展,提出“容器池”概念,假设了它的构建模型。在实际例子中进行应用和分析,分别探讨了在同一流程下数据共享和不同流程下数据共享的两种应用情形。     

基于区块链的数据治理协同方法

针对当前数据治理过程中面临的数据标准不统一、数据质量良莠不齐以及数据安全隐私凸显等问题,提出一种基于区块链的数据治理协同方法,将区块链多方协作、安全可信等特性应用到数据标准的构建、数据安全的保障和数据共享过程的控制。本方法首先根据数据治理要求和区块链特征,提炼形成基于区块链的数据治理协同模型,通过构建多方协作的数据标准流程、数据标准构建和更新机制、安全可靠的数据共享和访问控制等,实现区块链数据治理协同方法,从而提升数据标准化工作的效率和安全性。实验及分析结果表明,该方法比传统的数据标准构建方法在标准用语申请时间效率上有明显的提升,特别是在大数据环境下,基于区块链智能合约的方法对时间效率提升更为明显,基于区块链的分布式存储等特性为系统的安全、用户行为追溯和审计提供了有力依据和保障。该方案对于数据治理工作具有良好的应用示范效果,为行业的元数据管理、数据标准的共享和应用提供了借鉴思路。     

A business repository enrichment process: A case study for manufacturing execution systems

A key characteristic of the software applications supporting manufacturing business processes is their heterogeneity. This is due not only to differences in their development and deployment, but also to the variety of processes and actors in complex organizations. Heterogeneity at the semantic level is one of the major problems in any process of interoperability and/or integration. There is therefore a need for developing new approaches and methods to ensure interoperability between different software solutions. In the context of a case study with a consortium of MES (Manufacturing Execution Systems) publishers, we propose a semantic alignment process of repositories used in the construction of a MES solution called “MES On Demand”, using multiple applications and driven by business processes. Through the study of semantic heterogeneities, we use an enrichment-based alignment for business repositories applied to ISO/IEC 62264. Finally, we evaluate the contribution of this approach to enterprise maturity in the application of standards and reference models, using Nascio’s Enterprise Architecture Maturity Model. This proposal, which is useful for practitioners and experts, is a contribution to academic study on semantic alignment for master interoperability.     

基于区块链的去中心化身份认证及密钥管理方案

SM9是国内商用密码体系的重要组成部分,它是基于标识的密码体制,可以避免PKI系统中复杂的证书管理难题,为物联网安全应用提供了新的解决方案。但SM9需要可信第三方KGC为用户生成和管理密钥,密钥更新极为不便。为了解决SM9密钥更新的难题,文章利用区块链技术,提出一种去中心化的身份认证及密钥管理方案。在该方案中,用户仅需要首次由IGC(Identity Generator Center)为其生成身份标识符和密钥,随后用户可以自动对密钥更新,在此过程中身份标识符作为公钥保持不变,仅对私钥和参数更新,以便于身份认证。文章重新定义了交易的数据结构,并且更新过程以交易的形式记录在区块链上,通过区块链数据的不可篡改性保证了其真实可信。文章的研究为去中心化的物联网应用场景下身份认证及密钥管理提供了新的解决方案。     

Analyzing business process anomalies using autoencoders

Businesses are naturally interested in detecting anomalies in their internal processes, because these can be indicators for fraud and inefficiencies. Within the domain of business intelligence, classic anomaly detection is not very frequently researched. In this paper, we propose a method, using autoencoders, for detecting and analyzing anomalies occurring in the execution of a business process. Our method does not rely on any prior knowledge about the process and can be trained on a noisy dataset already containing the anomalies. We demonstrate its effectiveness by evaluating it on 700 different datasets and testing its performance against three state-of-the-art anomaly detection methods. This paper is an extension of our previous work from 2016 (Nolle et al. in Unsupervised anomaly detection in noisy business process event logs using denoising autoencoders. In: International conference on discovery science, Springer, pp 442–456, 2016). Compared to the original publication we have further refined the approach in terms of performance and conducted an elaborate evaluation on more sophisticated datasets including real-life event logs from the Business Process Intelligence Challenges of 2012 and 2017. In our experiments our approach reached an \(F_1\) score of 0.87, whereas the best unaltered state-of-the-art approach reached an \(F_1\) score of 0.72. Furthermore, our approach can be used to analyze the detected anomalies in terms of which event within one execution of the process causes the anomaly.     

利用Debug调试汇编语言程序执行过程的教学探讨

“微机原理与接口技术”是电子电气信息类专业的一门核心课程,是一门软件与硬件、理论与实践相结合的课程.学生普遍感到其内容庞杂、对计算机底层的工作原理难以理解、学习难度大.为此,提出利用Debug调试程序对汇编语言程序的执行过程进行深入地跟踪分析,从而促进学生对计算机底层工作原理的理解,实践证明这种方法能有效地激发学生学习的兴趣,取得了良好的教学效果.     

On business process monitoring using cross-flow coordination

This paper presents an approach for monitoring the execution progress of business processes. The monitoring focuses on the exceptions that could arise during this execution and, hence, could make the processes fail if not handled properly and timely. The approach relies on three flows known as control, communication, and navigation. The control flow connects tasks together with respect to a certain business logic. The communication flow captures the messages exchanged between persons/machines when they perform tasks of processes. Finally, the navigation flow captures the interactions between specialized networks that offer solutions to exceptions. These networks are built upon relations between tasks, between persons, and between machines. The coordination of control, communication, and navigation flows focuses on both the actions that are taken and the messages that are exchanged when handling exceptions. A system demonstrating flow development and coordination is, also, presented in the paper.     

基于信息量的分布式协同自组织算法

无线传感器网络中节点协同自组织主要涵盖传感器管理和状态估计,也就是如何选择传感器节点、设置传感器参数并估计被监测系统的状态,因此协同白组织为决策与估计的联合优化．本文提出了一种自适应动态协同自组织算法,以量测所提供的信息量和节点自身的剩余能量做为节点选择的综合指标,根据设定的感知精度,自适应地选择参与感知任务的节点集合,在信息滤波的融合框架下完成状态的分布式估计．相比信息驱动传感器查询（information-driven sensor querying,IDSQ）,算法具有精度可调、强鲁棒,同时尽可能地延长了网络的生命周期．以目标跟踪为应用背景,其仿真结果表明：以跟踪精度、失跟率和网络生命周期作为评价指标,该算法优于IDSQ．     

Decentralized multi-dimensional alert correlation for collaborative intrusion detection

The growth in coordinated network attacks such as scans, worms and distributed denial-of-service (DDoS) attacks is a profound threat to the security of the Internet. Collaborative intrusion detection systems (CIDSs) have the potential to detect these attacks, by enabling all the participating intrusion detection systems (IDSs) to share suspicious intelligence with each other to form a global view of the current security threats. Current correlation algorithms in CIDSs are either too simple to capture the important characteristics of attacks, or too computationally expensive to detect attacks in a timely manner. We propose a decentralized, multi-dimensional alert correlation algorithm for CIDSs to address these challenges. A multi-dimensional alert clustering algorithm is used to extract the significant intrusion patterns from raw intrusion alerts. A two-stage correlation algorithm is used, which first clusters alerts locally at each IDS, before reporting significant alert patterns to a global correlation stage. We introduce a probabilistic approach to decide when a pattern at the local stage is sufficiently significant to warrant correlation at the global stage. We then implement the proposed two-stage correlation algorithm in a fully distributed CIDS. Our experiments on a large real-world intrusion data set show that our approach can achieve a significant reduction in the number of alert messages generated by the local correlation stage with negligible false negatives compared to a centralized scheme. The proposed probabilistic threshold approach gains a significant improvement in detection accuracy in a stealthy attack scenario, compared to a naive scheme that uses the same threshold at the local and global stages. A large scale experiment on PlanetLab shows that our decentralized architecture is significantly more efficient than a centralized approach in terms of the time required to correlate alerts.     

The impact of blockchain on business models in banking

Information Systems and e-Business Management - Blockchain technology is predicted to reshape existing business models of the financial services industry. But although blockchain is often seen as a...