Showing papers on "Workflow published in 2007"

Interoperable systems and methods for peer-to-peer service orchestration

Abstract: Systems and methods are described for performing policy-managed, peer-to-peer service orchestration in a manner that supports the formation of self-organizing service networks that enable rich media experiences. In one embodiment, services are distributed across peer-to-peer communicating nodes, and each node provides message routing and orchestration using a message pump and workflow collator. Distributed policy management of service interfaces helps to provide trust and security, supporting commercial exchange of value. Peer-to-peer messaging and workflow collation allow services to be dynamically created from a heterogeneous set of primitive services. The shared resources are services of many different types, using different service interface bindings beyond those typically supported in a web service deployments built on UDDI, SOAP, and WSDL. In a preferred embodiment, a media services framework is provided that enables nodes to find one another, interact, exchange value, and cooperate across tiers of networks from WANs to PANs.

Examining the Challenges of Scientific Workflows

Abstract: Workflows have emerged as a paradigm for representing and managing complex distributed computations and are used to accelerate the pace of scientific progress. A recent National Science Foundation workshop brought together domain, computer, and social scientists to discuss requirements of future scientific applications and the challenges they present to current workflow technologies.

DECLARE: Full Support for Loosely-Structured Processes

Abstract: Traditional workflow management systems (WFMSs) are not flexible enough to support loosely-structured processes. Furthermore, flexibility in contemporary WFMSs usually comes at a certain cost, such as lack of support for users, lack of methods for model analysis, lack of methods for analysis of past executions, etc. DECLARE is a proto-type of a WFMS that uses a constraint-based process modeling language for the development of declarative models describing loosely-structured processes. In this paper we show how DECLARE can support loosely-structured processes without sacrificing important WFMSs features like user support, model verification, analysis of past executions, changing models at run-time, etc.

Workflows For E-Science: Scientific Workflows For Grids

Abstract: This is a timely book presenting an overview of the current state-of-the-art within established projects, presenting many different aspects of workflow from users to tool builders. It provides an overview of active research, from a number of different perspectives. It includes theoretical aspects of workflow and deals with workflow for e-Science as opposed to e-Commerce. The topics covered will be of interest to a wide range of practitioners.

Constraint-based workflow models: change made easy

Abstract: The degree of flexibility of workflow management systems heavily influences the way business processes are executed. Constraint-based models are considered to be more flexible than traditional models because of their semantics: everything that does not violate constraints is allowed. Although constraint-based models are flexible, changes to process definitions might be needed to comply with evolving business domains and exceptional situations. Flexibility can be increased by run-time support for dynamic changes - transferring instances to a new model - and ad-hoc changes - changing the process definition for one instance. In this paper we propose a general framework for a constraint-based process modeling language and its implementation. Our approach supports both ad-hoc and dynamic change, and the transfer of instances can be done easier than in traditional approaches.

The Triana Workflow Environment: Architecture and Applications

Abstract: In this chapter, the Triana workflow environment is described. Triana focuses on supporting services within multiple environments, such as peer-to-peer (P2P) and the Grid, by integrating with various types of middleware toolkits. This approach differs from that of the last chapter, which gave an overview of Taverna, a system designed to support scientists using Grid technology to conduct in silico experiments in biology. Taverna focuses workflow at the Web services level and addresses concerns of how such services should be presented to its users.

Scientific workflow: a survey and research directions

Abstract: Workflow technologies are emerging as the dominant approach to coordinate groups of distributed services. However with a space filled with competing specifications, standards and frameworks from multiple domains, choosing the right tool for the job is not always a straightforward task. Researchers are often unaware of the range of technology that already exists and focus on implementing yet another proprietary workflow system. As an antidote to this common problem, this paper presents a concise survey of existing workflow technology from the business and scientific domain and makes a number of key suggestions towards the future development of scientific workflow systems.

AO4BPEL: An Aspect-oriented Extension to BPEL

Abstract: Process-oriented composition languages such as BPEL allow Web Services to be composed into more sophisticated services using a workflow process. However, such languages exhibit some limitations with respect to modularity and flexibility. They do not provide means for a well-modularized specification of crosscutting concerns such as logging, persistence, auditing, and security. They also do not support the dynamic adaptation of composition at runtime. In this paper, we advocate an aspect-oriented approach to Web Service composition and present the design and implementation of AO4BPEL, an aspect-oriented extension to BPEL. We illustrate through examples how AO4BPEL makes the composition specification more modular and the composition itself more flexible and adaptable.

Scheduling Workflows with Budget Constraints

Abstract: Grids are emerging as a promising solution for resource and computation demanding applications. However, the heterogeneity of resources in Grid computing, complicates resource management and scheduling of applications. In addition, the commercialization of the Grid requires policies that can take into account user requirements, and budget considerations in particular. This paper considers a basic model for workflow applications modelled as Directed Acyclic Graphs (DAGs) and investigates heuristics that allow to schedule the nodes of the DAG (or tasks of a workflow) onto resources in a way that satisfies a budget constraint and is still optimized for overall time. Two different approaches are implemented, evaluated and presented using four different types of basic DAGs.

A survey of comparative business process modeling approaches

Abstract: There has been a huge influx of business process modeling langu ages as business process management (BPM) and process-aware information systems continue to expand into various business domains. The origins of process modeling languages are quite diverse, although two dominant approaches can be observed; one based on graphical models, and the other based on rule specifications. However, at this time, there is no report in literature that specifically targets a comparative analysis of these two approaches, on aspects such as the relative areas of application, power of expression, and limitations. In this paper we have attempted to address this question. We will present both a survey of the two approaches as well as a critical and comparative analysis.

The hidden order of wikipedia

Abstract: We examine the procedural side of Wikipedia, the well-known internet encyclopedia. Despite the lack of structure in the underlying wiki technology, users abide by hundreds of rules and follow well-defined processes. Our case study is the Featured Article (FA) process, one of the best established procedures on the site. We analyze the FA process through the theoretical framework of commons governance, and demonstrate how this process blends elements of traditional workflow with peer production. We conclude that rather than encouraging anarchy, many aspects of wiki technology lend themselves to the collective creation of formalized process and policy.

Swaddler: an approach for the anomaly-based detection of state violations in web applications

Abstract: In recent years, web applications have become tremendously popular, and nowadays they are routinely used in security-critical environments, such as medical, financial, and military systems. As the use of web applications for critical services has increased, the number and sophistication of attacks against these applications have grown as well. Most approaches to the detection of web-based attacks analyze the interaction of a web application with its clients and back-end servers. Even though these approaches can effectively detect and block a number of attacks, there are attacks that cannot be detected only by looking at the external behavior of a web application. In this paper, we present Swaddler, a novel approach to the anomaly-based detection of attacks against web applications. Swaddler analyzes the internal state of a web application and learns the relationships between the application's critical execution points and the application's internal state. By doing this, Swaddler is able to identify attacks that attempt to bring an application in an inconsistent, anomalous state, such as violations of the intended workflow of a web application. We developed a prototype of our approach for the PHP language and we evaluated it with respect to several real-world applications.

Information workflow for a medical diagnostic workstation

Abstract: An information workflow for a medical diagnostic workstation in which patient data is captured, arranged and displayed in predetermined formats for a user in the handling of patients. The workflow permits vitals capture and storage and. creation of a comprehensive patient record in which the workstation can operate in a stand-alone or network connected mode.

Software Development Environments for Scientific and Engineering Software: A Series of Case Studies

Abstract: The need for high performance computing applications for computational science and engineering projects is growing rapidly, yet there have been few detailed studies of the software engineering process used for these applications. The DARPA High Productivity Computing Systems Program has sponsored a series of case studies of representative computational science and engineering projects to identify the steps involved in developing such applications (i.e. the life cycle, the workflows, technical challenges, and organizational challenges). Secondary goals were to characterize tool usage and identify enhancements that would increase the programmers' productivity. Finally, these studies were designed to develop a set of lessons learned that can be transferred to the general computational science and engineering community to improve the software engineering process used for their applications. Nine lessons learned from five representative projects are presented, along with their software engineering implications, to provide insight into the software development environments in this domain.

Business process map management

Abstract: Methods and apparatuses enable providing a workflow management environment that provides different workflow management perspectives with different views on a variety of reusable workflow components or workflow resources. The different views may include a swim lane view having multiple separate sections that each represents a different performer, and a list view that represents the resources in transactional order. The workflow management environment defines reusable workflow components and associates the components with the different performers and with each other. The defining of the components and the relationships can define a portion of a workflow.

Multi-objective planning for workflow execution on Grids

Abstract: Utility grids create an infrastructure for enabling users to consume services transparently over a global network. When optimizing workflow execution on utility grids, we need to consider multiple quality of service (QoS) parameters including service prices and execution time. These optimization objectives may be in conflict. In this paper, we have proposed a workflow execution planning approach using multi-objective evolutionary algorithms (MOEAs). Our goal was to generate a set of trade-off scheduling solutions according to the users QoS requirements. The alternative trade-off solutions offer more flexibility to users when estimating their QoS requirements of workflow executions. Simulation results show that MOEAs are able to find a range of compromise solutions in a short computational time.

ASKALON: A Development and Grid Computing Environment for Scientific Workflows

Abstract: Most existing Grid application development environments provide the application developer with a nontransparent Grid Commonly, application developers are explicitly involved in tedious tasks such as selecting software components deployed on specific sites, mapping applications onto the Grid, or selecting appropriate computers for their applications Moreover, many programming interfaces are either implementation-technology-specific (eg, based on Web services [24]) or force the application developer to program at a low-level middleware abstraction (eg, start task, transfer data [22, 153]) While a variety of graphical workflow composition tools are currently being proposed, none of them is based on standard modeling techniques such as Unified Modeling Language (UML)

Workflow Management in Condor

Abstract: The Condor project began in 1988 and has evolved into a feature-rich batch system that targets high-throughput computing; that is, Condor ([262], [414]) focuses on providing reliable access to computing over long periods of time instead of highly tuned, high-performance computing for short periods of time or a small number of applications.

myExperiment: social networking for workflow-using e-scientists

Abstract: We present the Taverna workflow workbench and argue that scientific workflow environments need a rich ecosystem of tools that support the scientists. experimental lifecycle. Workflows are scientific objects in their own right, to be exchanged and reused. myExperiment is a new initiative to create a social networking environment for workflow workers. We present the motivation for myExperiment and sketch the proposed capabilities and challenges. We argue that actively engaging with a scientist's needs, fears and reward incentives is crucial for success.

Empowering collaborative commerce with Web services enabled business process management systems

Abstract: Collaborative commerce (C-Commerce) is a set of technologies and business practices that allows companies to build stronger relationships with their trading partners through integrating complex and cross-enterprise processes governed by business logic and rules, as well as workflows. Business Process Management (BPM) is a key element of C-Commerce solutions for complex process coordination. It provides a mechanism to support e-businesses in modeling, deploying, and managing business processes that involve various applications with greater flexibility. Traditional BPM solutions often lack the capability to integrate external applications in that they have very limited support for interoperability. In recent years, Web services have emerged as a promising enabling technology for BPM in support of C-Commerce. Web services offer effective and standard-based means to improve interoperability among different software applications over Internet protocols. This paper aims to give an in-depth analysis of BPM and Web services in the context of C-Commerce. We propose an architecture for Web services enabled BPM in C-Commerce and provide technical insights into why Web services can enhance business process coordination. Finally, an implementation of a dynamic e-procurement application based on the proposed architecture is presented. With the advent of Web service standards and business process integration tools that support them, BPM systems enabled by Web services are empowering the development of more flexible and dynamic C-Commerce.

A Dynamic Critical Path Algorithm for Scheduling Scientific Workflow Applications on Global Grids

Abstract: Effective scheduling is a key concern for the execution of performance driven grid applications. In this paper, we propose a dynamic critical path (DCP) based workflow scheduling algorithm that determines efficient mapping of tasks by calculating the critical path in the workflow task graph at every step. It assigns priority to a task in the critical path which is estimated to complete earlier. Using simulation, we have compared the performance of our proposed approach with other existing heuristic and meta-heuristic based scheduling strategies for different type and size of workflows. Our results demonstrate that DCP based approach can generate better schedule for most of the type of workflows irrespective of their size particularly when resource availability changes frequently.

Wings for Pegasus: creating large-scale scientific applications using semantic representations of computational workflows

Abstract: Scientific workflows are being developed for many domains as a useful paradigm to manage complex scientific computations. In our work, we are challenged with efficiently generating and validating workflows that contain large amounts (hundreds to thousands) of individual computations to be executed over distributed environments. This paper describes a new approach to workflow creation that uses semantic representations to describe compactly complex scientific applications in a dataindependent manner, then automatically generates workflows of computations for given data sets, and finally maps them to available computing resources. The semantic representations are used to automatically generate descriptions for each of the thousands of new data products. We interleave the creation of the workflow with its execution, which allows intermediate execution data products to influence the generation of the following portions of the workflow. We have implemented this approach in Wings, a workflow creation system that combines semantic representations with planning techniques. We have used Wings to create workflows of thousands of computations, which are submitted to the Pegasus mapping system for execution over distributed computing environments. We show results on an earthquake simulation workflow that was automatically created with a total number of 24,135 jobs and that executed for a total of 1.9 CPU years.

Deadline-based escalation in process-aware information systems

Abstract: Decision making in process-aware information systems involves build-time and run-time decisions. At build-time, idealized process models are designed based on the organization's objectives, infrastructure, context, constraints, etc. At run-time, this idealized view is often broken. In particular, process models generally assume that planned activities happen within a certain period. When such assumptions are not fulfilled, users must make decisions regarding alternative arrangements to achieve the goal of completing the process within its expected time frame or to minimize tardiness. We refer to the required decisions as escalations. This paper proposes a framework for escalations that draws on established principles from the workflow management field. The paper identifies and classifies a number of escalation mechanisms such as changing the routing of work, changing the work distribution or changing the requirements with respect to available data. A case study and a simulation experiment are used to illustrate and evaluate these mechanisms.

Scheduling Data-IntensiveWorkflows onto Storage-Constrained Distributed Resources

Abstract: In this paper we examine the issue of optimizing disk usage and of scheduling large-scale scientific workflows onto distributed resources where the workflows are data- intensive, requiring large amounts of data storage, and where the resources have limited storage resources. Our approach is two-fold: we minimize the amount of space a workflow requires during execution by removing data files at runtime when they are no longer required and we schedule the workflows in a way that assures that the amount of data required and generated by the workflow fits onto the individual resources. For a workflow used by gravitational- wave physicists, we were able to improve the amount of storage required by the workflow by up to 57 %. We also designed an algorithm that can not only find feasible solutions for workflow task assignment to resources in disk- space constrained environments, but can also improve the overall workflow performance.

System and method for performing oilfield simulation operations

Abstract: The invention relates to a method of performing production operations of an oilfield having at least one process facility and at least one wellsite operatively connected thereto, each at least one wellsite having a wellbore penetrating a subterranean formation for extracting fluid from an underground reservoir therein. The method steps include receiving a number of steps each from at least one of a number of collaborators, specifying an automated workflow including the number of steps and for generating a first well plan, obtaining first data associated with the production operations, applying the automated workflow to the first data to generate the first well plan, adjusting the production operations based on the first well plan, and modifying at least one of the number of steps based on input from at least one of the number of collaborators to generate an updated automated workflow.