Process Execution Engine Research Articles

Using BPMN to model Internet of Things behavior within business process

Whereas, traditionally, business processes use the Internet of Things (IoTs) as a distributed source of information, the increase of computational capabilities of IoT devices provides them with the means to also execute parts of the business logic, reducing the amount of exchanged data and central processing. Current approaches based on Business Process Model and Notation (BPMN) already support modelers to define both business processes and IoT devices behavior at the same level of abstraction. However, they are not restricted to standard BPMN elements and they generate IoT device specific low-level code. The work we present in this paper exclusivelly uses standard BPMN to define central as well as IoT behavior of business processes. In addition, the BPMN that defines the IoT behavior is translated to a neutral-platform programming code. The deployment and execution environments use Web services to support the communication between the process execution engine and IoT devices.

Enabling runtime flexibility in data-centric and data-driven process execution engines

Contemporary process management systems support users during the execution of predefined business processes. However, when unforeseen situations occur, which are not part of the process model serving as the template for process execution, contemporary technology is often unable to offer adequate user support. One solution to this problem is to allow for ad-hoc changes to process models, i.e., changes that may be applied on the fly to a running process instance. As opposed to the widespread activity-centric process modeling paradigm, for which the support of instance-specific ad-hoc changes is well researched, albeit not properly supported by most commercial process engines, there is no corresponding support for ad-hoc changes in other process support paradigms, such as artifact-centric or object-aware process management. This article presents concepts for supporting ad-hoc changes in data-centric and data-driven processes, and gives insights into the challenges to be tackled when implementing this kind of process flexibility in the PHILharmonicFlows process execution engine. We evaluated the concepts by implementing a proof-of-concept prototype and applying it to various scenarios. The development of advanced flexibility features is highly relevant for data-centric processes, as the research field is generally perceived as having low maturity compared to activity-centric processes.

A Blockchain-based and resource-aware process execution engine

Abstract Business Process Management provides concepts for enterprises to design, document and execute their business processes. Involved artefacts establish the basis for a profound enhancement of processes, like performance improvements or a substantiate assignment of employees (resources) to tasks. These artefacts comprise process models for documentation purposes or Workflow Management Systems for executing processes. Those concepts are adopted well within single companies but are barely implemented for inter-organizational processes reasoned in a lack of trust between participating business partners. For instance, questions like who the host of the workflow engine is and thus have sovereignty over the process execution remains open. Besides expensive third parties, we believe that Blockchain Technology bears potential to solve the lack of trust due to automated consensus finding. We present a Blockchain-based process engine guaranteeing a tamper-proof execution, which is both, highly scalable regarding the size of process models as well as capable of considering employees captured in the organizational perspective of the process model. Comparable approaches suffer from lack of trustworthiness either, are not applicable for large process models, or do not include organizational concerns.

Caterpillar: A business process execution engine on the Ethereum blockchain

SummaryBlockchain 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.

EDUC8 pathways: executing self-evolving and personalized intra-organizational educational processes

One of the main challenges to be confronted by modern tertiary sector, so as to improve quality is the personalization of learning, which has to be combined with a minimization of the respective costs. However, personalization requires continuous reconfiguration of the academic plans since the academic status of each student, educational options and circumstances inside a Higher Educational Institution constantly change. In this paper, we present EDUC8 (EDUCATE) software environment that provides an integrated information technology solution concerning the dynamic recommendation and execution of personalized education processes. The implemented EDUC8 prototype aggregates a process execution engine, a rule engine and a semantic infrastructure for reconfiguring the learning pathways for each student. The semantic infrastructure consists of an ontology enclosing the required knowledge and a semantic rule-set. During the execution of learning pathways, the system reasons over the rules and reconfigures the next steps of the learning process. At the same time, new knowledge and facts originated from both the rule base and the learning pathway meta-models that are established during their execution are created, which constitute the evolving knowledge base of EDUC8 platform. The completeness and performance of the implemented infrastructure was tested for the modeling and selection of a set of appropriate academic recommendations regarding the Network Engineering specialization field of the Computer Science program.

Edge Process Management: A case study on adaptive task scheduling in mobile IoT

Service-oriented standards and architectures provide a useful way of interfacing Internet of Things (IoT) devices with each other and outside applications, while managing the IoT-related automation and decision-making. Specifically, Business Process Management Systems (BPMS) and its’ standards (e.g. BPMN 2.0) help model the composition of devices and tasks involved in an IoT workflow. The conventional centralized BPMS architecture, where remote servers handle decision-making and orchestration, does not fit IoT paradigms such as Edge- and Fog Computing, where adaptability and de-centralized processing is required. Edge Process Management (EPM) aims to adapt BPMS to such requirements. For instance, in case the users smartphone is executing processes involving communication with nearby fog servers, the process execution engine needs to consider user mobility and available fog servers to ensure energy-efficient and adaptive edge process execution. We propose an EPM system architecture featuring a delay-aware fog server selection scheme that optimizes cost-efficiency of edge processes based on run-time context factors such as user movement, fog server load and location. We demonstrate a prototype implementation using this scheme alongside existing BPMS software and evaluate the performance of the server selection with simulated experiments, showing how interrupted connections are avoided and energy efficiency is improved.

A novel integrated approach to the execution of personalized and self-evolving learning pathways

One of the main challenges to be confronted by Higher Educational Institutions (HEI), so as to increase quality, is the provision of personalized education services in a wide range of educational settings, often beyond the course sequences historically offered to students. However, this personalization requires the continuous reconfiguration and adaptation of the selected academic plans, since each student is a unique case and both the educational options and current circumstances inside an educational institution change rapidly. In this paper, we present an innovative software environment offered to the academic staff and personnel that provides an integrated information technology solution concerning the dynamic and personalized composition of students’ learning pathways during execution phase. The software environment comprises a process execution engine based on a semantic infrastructure (ontology) for configuring the learning pathways. During the execution of learning pathways, the system reasons over the rules and dynamically recommends the next steps of the learning. The implemented graphical user interface and the respective business logic for the recommendation and execution of the learning pathway processes is presented, alongside with a graphical rule generator interface for the definition of the rule-set for the learning pathways in a user-friendly way.

Dynamic Execution of a Business Process via Web Service Selection and Orchestration

Dynamic execution of a business process requires the selection and composition of multiple existing services regardless of their locations, platforms, execution speeds, etc. Thus web service selection appears as a challenging and elusive task especially when the service task has to be executed based on user requirements at the runtime. This paper presents our Semantic-Based Business Process Execution Engine (SBPEE) for the dynamic execution of business processes by the orchestration of various exposed web services. SBPEE is based on our designed Project Domain Ontology (PrjOnt) that captures user specifications and SWRL rules which classify the user specification into a specific category according to the business logic and requirements of an enterprise. Based on this classification of the user project and requirements, our semantic engine selects web services from the service repository for the dynamic execution of a business process. SBPEE matches functional requirements of a web service and required QoS attributes to identify the list of pertinent candidate services to fulfil the complex business process transactions. Finally, we present our case study on Create Order business process that aims at creating an order for the customer by following various web services for its task completion.

High‐performance execution of service compositions: a multicore‐aware engine design

SUMMARYAlthough modern computer hardware offers an increasing number of processing elements organized in nonuniform memory access (NUMA) architectures, prevailing middleware engines for executing business processes, workflows, and Web service compositions have not been optimized for properly exploiting the abundant processing resources of such machines. Amongst others, factors limiting performance are inefficient thread scheduling by the operating system, which can result in suboptimal use of system memory and CPU caches, and sequential code sections that cannot take advantage of multiple available cores.In this article, we study the performance of the JOpera process execution engine on recent multicore machines. We first evaluate its performance without any dedicated optimization for multicore hardware, showing that additional cores do not significantly improve performance, although the engine has a multithreaded design. Therefore, we apply optimizations on the basis of replication together with an improved, hardware‐aware usage of the underlying resources such as NUMA nodes and CPU caches. Thanks to our optimizations, we achieve speedups from a factor of 2 up to a factor of 20 (depending on the target machine) when compared with a baseline execution ‘as is’. Copyright © 2012 John Wiley & Sons, Ltd.

Management of interactive business processes in decentralized service infrastructures through event processing

Several independent service providers often form decentralized service infrastructures. However, efficient management and collaboration is impossible, if the execution engines are not properly connected. The decentralized approach requires an infrastructure that connects the engines and additionally provides management access to the infrastructure and processes executed. When business processes are executed using multiple process execution engines, monitoring and management of these processes become impossible using standard tools. Therefore, management by an organization providing a common platform integrating the different service providers is required. In this paper, we present an approach and an implementation of such a service platform, using a complex event processing (CEP) engine to integrate different process execution engines and other applications. In such a setting, it becomes even irrelevant if process execution is based on the Web Service Business Process Execution Language (WS-BPEL) or the executable Business Process Model and Notation (BPMN). As being able to interact with such processes and running services is crucial in such an infrastructure, we provide a concept for creating ad-hoc user interactions on a monitoring dashboard, which allows platform managers as well as stakeholders in the processes to interact with the platform and the processes executed – independent of their execution context.

A Holistic Environment for the Design and Execution of Self-Adaptive Clinical Pathways

One of the main challenges to be confronted by modern health care, so as to increase treatment quality, is the personalization of treatment. The treatment personalization requires the continuous reconfiguration and adaptation of the selected treatment schemes according to the "current" clinical status of each patient and "current" circumstances inside a health care organization that change rapidly, as well as the updated medical knowledge. In this paper, we present an innovative software environment that provides an integrated IT solution concerning the adaptation of health care processes (clinical pathways) during execution time. The software comprises a health care process execution engine assisted by a semantic infrastructure for reconfiguring the clinical pathways. During the execution of clinical pathways, the system reasons over the rules and reconfigures the next steps of the treatment. A graphical designer interface is implemented for the definition of the rule-set for the clinical pathways adaptation in a user-friendly way.

RESTful Web service composition with BPEL for REST

Current Web service technology is evolving towards a simpler approach to define Web service APIs that challenges the assumptions made by existing languages for Web service composition. RESTful Web services introduce a new kind of abstraction, the resource, which does not fit well with the message-oriented paradigm of the Web service description language (WSDL). RESTful Web services are thus hard to compose using the Business Process Execution Language (WS-BPEL), due to its tight coupling to WSDL. The goal of the BPEL for REST extensions presented in this paper is twofold. First, we aim to enable the composition of both RESTful Web services and traditional Web services from within the same process-oriented service composition language. Second, we show how to publish a BPEL process as a RESTful Web service, by exposing selected parts of its execution state using the REST interaction primitives. We include a detailed example on how BPEL for REST can be applied to orchestrate a RESTful e-Commerce scenario and discuss how the proposed extensions affect the architecture of a process execution engine.

On managing business processes variants

Variance in business process execution can be the result of several situations, such as disconnection between documented models and business operations, workarounds in spite of process execution engines, dynamic change and exception handling, flexible and ad-hoc requirements, and collaborative and/or knowledge intensive work. It is imperative that effective support for managing process variances be extended to organizations mature in their BPM (business process management) uptake so that they can ensure organization wide consistency, promote reuse and capitalize on their BPM investments. This paper presents an approach for managing business processes that is conducive to dynamic change and the need for flexibility in execution. The approach is based on the notion of process constraints. It further provides a technique for effective utilization of the adaptations manifested in process variants. In particular, we will present a facility for discovery of preferred variants through effective search and retrieval based on the notion of process similarity, where multiple aspects of the process variants are compared according to specific query requirements. The advantage of this approach is the ability to provide a quantitative measure for the similarity between process variants, which further facilitates various BPM activities such as process reuse, analysis and discovery.

효율적인 비즈니스 프로세스 관리를 위한 J2EE 기반 B2Bi 협업 워크플로우 시스템 설계 및 구현

In this paper, the business process was easily modeled by distinguishing between the business process and work logic. Based on this model, B2Bi collaboration Workflow modeling tool, which facilitates collaboration, was designed and implemented. The collaboration workflow modeling tool consists of 3 components; business process modeling tool, execution engine and monitoring tool. First, a business process modeling tool is used to build a process map that reflects the business logic of an application in a quick and accurate manner. Second an execution engine provides a real-time execution environment for business process instance. Third, a monitoring tool provides a real-time monitoring function for the business process that is in operation at the time. In addition to this, it supports flexibility and expandability based on XML and J2EE for the linkage with the legacy system that was used previously, and suggests a solution for a new corporate strategy and operation.

IPM-EPDL: an XML-based executable process definition language

The capability to quickly design and deploy a new business process has become critical for companies to succeed in the rapidly changing global market. Web services are considered to be the most promising technology that enables automatic execution of business processes. It has some limitations, however, such as lack support for organizational structure and role model, customized user interface, access authorization of data, and storing instance data. This paper introduces Integrated Process Management Executable Process Definition Language (IPM-EPDL), an XML-based executable process definition language. IPM-EPDL supports flexible specification of organizational structure and role model. It allows the user to design the interface of a business process activity according to the number of users as well as their preferences, browser type, and type of the form to be used for the activity. It also enables to specify the access authorization of data and to check the validity of the data. Finally, it can specify all business data and keep it throughout the entire process lifecycle. Such data can be used for checking the status of process instance and for various analyses. The paper discusses how a typical process definition must be extended to enable its execution while providing the above advantages. The paper describes how the IPM-EPDL execution engine provides these capabilities. The paper also demonstrates a prototype system along with an extended example to illustrate that the proposed language and process execution engine can support rapid deployment of a new business process that can be performed on various platforms even by a remote user.

Development of Middle Agents Mediating Ubiquitous Environment and Web Services

According to the widespread use of Web Services, composition of multiple services is becoming a main issue. BPEL was proposed as a Web Services workflow language in this context. Then, in many cases we need much interactions between a service requester and a BPEL process execution engine. However for the end user under the ubiquitous environment where the service is executed with a cellular phone or PDA, the interaction means simply a burden. The reason is: (1)it is hard to carry out the operation manually, (2)a network connection is unstable, (3)a connection charge is relatively high. In this paper, we propose middle agents between ubiquitous users and Web Services. The agents analyze BPEL, extract the interaction which the ubiquitous users would need, then produce action operators. It makes a plan in order to achieve a service request from the user. Here the planning agent can reduce operations of the user by collecting the necessary information at the beginning which will be inputted during the IP execution. We show the architecture of the agents and an example regarding ATM service, then evaluate the number of inputs, the performance, and the quantity of data transmitted on network. Finally, we consider adaptability of this approach to generic BPEL flow.