A constraint specification approach to building flexible workflows

Process support systems, such as workflows, are being used in a variety of domains. However, most areas of application have focused on traditional production-style processes, which are characterised by predictability and repetitiveness. Application in non-traditional domains with highly flexible process is still largely unexplored. Such flexible processes are characterised by lack of ability to completely predefine and/or an explosive number of alternatives. Accordingly we define flexibility as the ability of the process to execute on the basis of a partially defined model where the full specification is made at runtime and may be unique to each instance. In this paper, we will present an approach to building workflow models for such processes. We will present our approach in the context of a non-traditional domain for workflow, deployment, which is, degree programs in tertiary institutes. The primary motivation behind our approach is to provide the ability to model flexible processes without introducing non-standard modelling constructs. This ensures that the correctness and verification of the language is preserved. We propose to build workflow schemas from a standard set of modelling constructs and given process constraints. We identify the fundamental requirements for constraint specification and classify them into selection, termination and build constraints. We will detail the specification of these constraints in a relational model. Finally, we will demonstrate the dynamic building of instance specific workflow models on the basis of these constraints

An investigation into the relevance of flexibility- and interoperability requirements for implementation processes for workflow-management-applications

Flexibility and Interoperability have become important characteristics for organisations and their business processes. The need to control flexible business processes within an organisation’s boundaries and between organisations imposes major requirements on a company’s process control capabilities. Workflow Management Systems (WFMS) try to fulfil these requirements by offering respective product features. Evidence suggests that the achievement of flexible business processes and an inter-organisational process control is also influenced by implementation processes for Workflow Management Applications (WFMA). [A WFMA comprises the WFMS and "all WFMS specific data with regard to one or more business processes" [VER01]]. The impact of a WFMA implementation methodology on the fulfilment of these requirements is the research scope of the project. The thesis provides knowledge in the following areas: 1. Review of the relationship between workflow management and the claim for process flexibility respectively -interoperability. 2. Definition of a research-/evaluation framework for workflow projects. This framework is composed of all relevant research variables that have been identified for the thesis. 3. Empirical survey of relevant workflow-project objectives and their priority in the context of process flexibility and –interoperability. 4. Empirical survey of the objectives’ achievement. 5. Empirical survey of methodologies / activities that have been applied within workflow projects. 6. Derivation of the project methodologies’ effectiveness in terms of the impact that applied activities had on project objectives. 7. Evaluation of existing workflow life-cycle models in accordance with the research framework. 8. Identification of basic improvements for workflow implementation processes with respect to the achievement of flexible and interoperable business processes. The first part of the thesis argues the relevance of the subject. Afterwards research variables that constitute the evaluation framework for WFMA implementation processes are stepwise identified and defined. An empirical study then proves the variables’ effectiveness for the achievement of process flexibility and –interoperability within the WFMA implementation process. After this the framework is applied to evaluate chosen WFMA implementation methodologies. Identified weaknesses and effective methodological aspects are utilised to develop generic methodological improvements. These improvements are later validated by means of a case study and interviews with workflow experts.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An investigation into the relevance of flexibility- and interoperability requirements for implementation processes for workflow-management-applications

Flexibility and Interoperability have become important characteristics for organisations and their business processes. The need to control flexible business processes within an organisation’s boundaries and between organisations imposes major requirements on a company’s process control capabilities. Workflow Management Systems (WFMS) try to fulfil these requirements by offering respective product features. Evidence suggests that the achievement of flexible business processes and an inter-organisational process control is also influenced by implementation processes for Workflow Management Applications (WFMA). [A WFMA comprises the WFMS and "all WFMS specific data with regard to one or more business processes" [VER01]]. The impact of a WFMA implementation methodology on the fulfilment of these requirements is the research scope of the project. The thesis provides knowledge in the following areas: 1. Review of the relationship between workflow management and the claim for process flexibility respectively -interoperability. 2. Definition of a research-/evaluation framework for workflow projects. This framework is composed of all relevant research variables that have been identified for the thesis. 3. Empirical survey of relevant workflow-project objectives and their priority in the context of process flexibility and –interoperability. 4. Empirical survey of the objectives’ achievement. 5. Empirical survey of methodologies / activities that have been applied within workflow projects. 6. Derivation of the project methodologies’ effectiveness in terms of the impact that applied activities had on project objectives. 7. Evaluation of existing workflow life-cycle models in accordance with the research framework. 8. Identification of basic improvements for workflow implementation processes with respect to the achievement of flexible and interoperable business processes. The first part of the thesis argues the relevance of the subject. Afterwards research variables that constitute the evaluation framework for WFMA implementation processes are stepwise identified and defined. An empirical study then proves the variables’ effectiveness for the achievement of process flexibility and –interoperability within the WFMA implementation process. After this the framework is applied to evaluate chosen WFMA implementation methodologies. Identified weaknesses and effective methodological aspects are utilised to develop generic methodological improvements. These improvements are later validated by means of a case study and interviews with workflow experts.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Two ways to Grid: the contribution of Open Grid Services Architecture (OGSA) mechanisms to service-centric and resource-centric lifecycles

Service Oriented Architectures (SOAs) support service lifecycle tasks, including Development, Deployment, Discovery and Use. We observe that there are two disparate ways to use Grid SOAs such as the Open Grid Services Architecture (OGSA) as exemplified in the Globus Toolkit (GT3/4). One is a traditional enterprise SOA use where end-user services are developed, deployed and resourced behind firewalls, for use by external consumers: a service-centric (or ‘first-order’) approach. The other supports end-user development, deployment, and resourcing of applications across organizations via the use of execution and resource management services: A Resource-centric (or ‘second-order’) approach. We analyze and compare the two approaches using a combination of empirical experiments and an architectural evaluation methodology (scenario, mechanism, and quality attributes) to reveal common and distinct strengths and weaknesses. The impact of potential improvements (which are likely to be manifested by GT4) is estimated, and opportunities for alternative architectures and technologies explored. We conclude by investigating if the two approaches can be converged or combined, and if they are compatible on shared resources

Event-Oriented Dynamic Adaptation of Workflows: Model, Architecture and Implementation

Workflow management is widely accepted as a core technology to support long-term business processes in heterogeneous and distributed environments. However, conventional workflow management systems do not provide sufficient flexibility support to cope with the broad range of failure situations that may occur during workflow execution. In particular, most systems do not allow to dynamically adapt a workflow due to a failure situation, e.g., to dynamically drop or insert execution steps. As a contribution to overcome these limitations, this dissertation introduces the agent-based workflow management system AgentWork. AgentWork supports the definition, the execution and, as its main contribution, the event-oriented and semi-automated dynamic adaptation of workflows. Two strategies for automatic workflow adaptation are provided. Predictive adaptation adapts workflow parts affected by a failure in advance (predictively), typically as soon as the failure is detected. This is advantageous in many situations and gives enough time to meet organizational constraints for adapted workflow parts. Reactive adaptation is typically performed when predictive adaptation is not possible. In this case, adaptation is performed when the affected workflow part is to be executed, e.g., before an activity is executed it is checked whether it is subject to a workflow adaptation such as dropping, postponement or replacement. In particular, the following contributions are provided by AgentWork: A Formal Model for Workflow Definition, Execution, and Estimation: In this context, AgentWork first provides an object-oriented workflow definition language. This language allows for the definition of a workflow\u92s control and data flow. Furthermore, a workflow\u92s cooperation with other workflows or workflow systems can be specified. Second, AgentWork provides a precise workflow execution model. This is necessary, as a running workflow usually is a complex collection of concurrent activities and data flow processes, and as failure situations and dynamic adaptations affect running workflows. Furthermore, mechanisms for the estimation of a workflow\u92s future execution behavior are provided. These mechanisms are of particular importance for predictive adaptation. Mechanisms for Determining and Processing Failure Events and Failure Actions: AgentWork provides mechanisms to decide whether an event constitutes a failure situation and what has to be done to cope with this failure. This is formally achieved by evaluating event-condition-action rules where the event-condition part describes under which condition an event has to be viewed as a failure event. The action part represents the necessary actions needed to cope with the failure. To support the temporal dimension of events and actions, this dissertation provides a novel event-condition-action model based on a temporal object-oriented logic. Mechanisms for the Adaptation of Affected Workflows: In case of failure situations it has to be decided how an affected workflow has to be dynamically adapted on the node and edge level. AgentWork provides a novel approach that combines the two principal strategies reactive adaptation and predictive adaptation. Depending on the context of the failure, the appropriate strategy is selected. Furthermore, control flow adaptation operators are provided which translate failure actions into structural control flow adaptations. Data flow operators adapt the data flow after a control flow adaptation, if necessary. Mechanisms for the Handling of Inter-Workflow Implications of Failure Situations: AgentWork provides novel mechanisms to decide whether a failure situation occurring to a workflow affects other workflows that communicate and cooperate with this workflow. In particular, AgentWork derives the temporal implications of a dynamic adaptation by estimating the duration that will be needed to process the changed workflow definition (in comparison with the original definition). Furthermore, qualitative implications of the dynamic change are determined. For this purpose, so-called quality measuring objects are introduced. All mechanisms provided by AgentWork include that users may interact during the failure handling process. In particular, the user has the possibility to reject or modify suggested workflow adaptations. A Prototypical Implementation: Finally, a prototypical Corba-based implementation of AgentWork is described. This implementation supports the integration of AgentWork into the distributed and heterogeneous environments of real-world organizations such as hospitals or insurance business enterprises

Dealing with Logical Failures for Collaborating Workflows

Logical failures occurring during workflow execution require the dynamic adaptation of affected workflows. The consequences such a dynamic adaptation may have for collaborating workflows have not yet been investigated sufficiently. We propose a rule-based approach for dynamic workflow adaptation to deal with logical failures. In our approach, workflow collaboration is based on agreements specifying the delivery time and quality of objects a workflow expects from its collaboration partners. Our mechanisms decide which collaborating workflows have to be informed when a dynamic adaptation is performed. In particular, we estimate the temporal and qualitative implications a dynamic adaptation has for collaboration partners. Because of the automated handling of logical failures, we expect that our approach significantly improves the robustness and correctness of collaborating workflows. The approach has been developed in the context of collaborative workflow-based care for cancer patients

Framework for a business interoperability quotient measurement model

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova da Lisboa para obtenção do grau de Mestre em Engenharia e Gestão Industrial (MEGI)Over the last decade the context of Interoperability has been changing rapidly. It has been expanding from the largely technically focused area of Information Systems towards Business Processes and Business Semantics. However, there exists a need for more comprehensive ways to define business interoperability and enable its performance measurement as a first step towards improvement of interoperability conditions between collaborating entities. Through extensive literature reviews and analysis of European Research initiatives in this area, this dissertation presents the State of the Art in Business Interoperability. The objective of this dissertation is to develop a model that closely captures the factors that are responsible for Business Interoperability in the context of Collaborative Business Processes. This Business Interoperability Quotient Measurement Model (BIQMM), developed in this dissertation uses an interdisciplinary approach to capture the key elements responsible for collaboration performance. Through the quantification of the relevance of each element to the particular collaboration scenario in question, this model enables a quantitative analysis of Business Interoperability, so that an overall interoperability score can be arrived at for enhanced performance measurements.Finally, the BIQMM is applied to a business case involving Innovayt and LM Glassfiber to demonstrate its applicability to different collaboration scenarios