Master of Science / Department of Computing and Information Sciences / Gurdip Singh / Developing an optimal working environment and managing the of work load in an efficient manner are the major challenges for most businesses today. So, the importance of the workflow and workflow management in an organization is unquestionable. Many organizations use sophisticated systems to organize the workflows. One such workflow system based on a concise and powerful modeling language called “Yet Another Workflow Language” is YAWL. YAWL handles complex data, transformations, integration with organizational resources and Web Service integration. Workflow comprises of three main perspectives: control-flow, data and the resources. In Yawl, the control-flow and the data-flow are tightly coupled within the workflow enactment engine. But the resource perspective is provided by a discrete custom service called Resource Service. Administrative tools are provided using which the administrator has to manually select the resource (referred as participant) which needs to perform a particular task of the workflow. This project aims at developing a service which can automate the assignment of the tasks to the participants by using the Resource service which provides number of interfaces that expose the full functionality of the service. The application of this project with respect to Healthcare domain is presented. Healthcare domain is the one of the most demanding and yet critical business process. Hospitals face increasing pressure to both improve the quality of the services delivered to patients and to reduce costs .Hence there is significant demand on hospitals in regard to how the organization, execution, and monitoring of work processes is performed. Workflow Management Systems like YAWL offers a potential solution as they support processes by managing the flow of work.

Master of Science / Department of Computing and Information Sciences / John Hatcliff / Like all businesses, clinical care groups and facilities are under a range of pressures to enhance the efficacy of their operations. Though there are a number of ways to go about these improvements, one exciting methodology involves the documentation and analysis of clinical workflows. Unfortunately, there is no industry standard tool which supports this, and many available workflow documentation technologies are not only proprietary, but technologically insufficient as well. Ideally, these workflows would be documented at a formal enough level to support their execution; this would allow the partial automation of documented clinical procedures. However, the difficulty involved in this automation effort is substantial: not only is there the irreducible complexity inherent to automation, but a number of the solutions presented so far layer on additional complication. To solve this, the author introduces Kinerja, a state-of-the-art execution environment for formally specified workflows. Operating on a subset of the academically and industrially proven workflow language YAWL, Kinerja allows for both human guided governance and computer guided verification of workflows, and allows for a seamless switching between modalities. Though the base of Kinerja is essentially an integrated framework allowing for considerable extensibility, a number of modules have already been developed to support the checking and executing of clinical workflows. One such module integrates symbolic execution which greatly optimizes the time and space necessary for a complete exploration of a workflow's state space.

Configurable process models are integrated representations of multiple variants of a process model in a given domain, e.g. multiple variants of a shipment-to-delivery process in the logistics domain. Configurable process models provide a basis for managing variability and for enabling reuse of process models in Process-Aware Information Systems. Rather than designing process models from scratch, analysts can derive process models by configuring existing ones, thereby reusing proven practices. This thesis starts with the observation that existing approaches for capturing and managing configurable process models suffer from three shortcomings that affect their usability in practice. Firstly, configuration in existing approaches is performed manually and as such it is error-prone. In particular, analysts are left with the burden of ensuring the correctness of the individualized models. Secondly, existing approaches suffer from a lack of decision support for the selection of configuration alternatives. Consequently, stakeholders involved in the configuration of process models need to possess expertise both in the application domain and in the modeling language employed. This assumption represents an adoption obstacle in domains where users are unfamiliar with modeling notations. Finally, existing approaches for configurable process modeling are limited in scope to control-flow aspects, ignoring other equally important aspects of process models such as object flow and resource management. Following a design science research method, this thesis addresses the above shortcomings by proposing an integrated framework to manage the configuration of process models. The framework is grounded on three original and interrelated contributions: (i) a conceptual foundation for correctness-preserving configuration of process models; (ii) a questionnaire-driven approach for process model configuration, providing decision support and abstraction from modeling notations; (iii) a meta-model for configurable process models covering control-flow, data objects and resources. While the framework is language-independent, an embodiment of the framework in the context of a process modeling language used in practice is also developed in this thesis. The framework was formally defined and validated using four scenarios taken from different domains. Moreover, a comprehensive toolset was implemented to support the validation of the framework.

Workflow Management Systems (WfMSs) are used to support the modelling, analysis, and enactment of business processes. The key benefits WfMSs seek to bring to an organisation include improved efficiency, better process control and improved customer service, which are realised by modelling rigidly structured business processes that in turn derive well-defined workflow process instances. However, the proprietary process definition frameworks imposed by WfMSs make it difficult to support (i) dynamic evolution and adaptation (i.e. modifying process definitions during execution) following unexpected or developmental change in the business processes being modelled; and (ii) exceptions, or deviations from the prescribed process model at runtime, even though it has been shown that such deviations are a common occurrence for almost all processes. These limitations imply that a large subset of business processes do not easily translate to the 'system-centric' modelling frameworks imposed. This research re-examines the fundamental theoretical principles that underpin workflow technologies to derive an approach that moves forward from the productionline paradigm and thereby offers workflow management support for a wider range of work environments. It develops a sound theoretical foundation based on Activity Theory to deliver an implementation of an approach for dynamic and extensible flexibility, evolution and exception handling in workflows, based not on proprietary frameworks, but on accepted ideas of how people actually perform their work activities. The approach produces a framework called worklets to provide an extensible repertoire of self-contained selection and exception-handling processes, coupled with an extensible ripple-down rule set. Using a Service-Oriented Architecture (SOA), a selection service provides workflow flexibility and adaptation by allowing the substitution of a task at runtime with a sub-process, dynamically selected from its repertoire depending on the context of the particular work instance. Additionally, an exceptionhandling service uses the same repertoire and rule set framework to provide targeted and multi-functional exception-handling processes, which may be dynamically invoked at the task, case or specification level, depending on the context of the work instance and the type of exception that has occurred. Seven different types of exception can be handled by the service. Both expected and unexpected exceptions are catered for in real time. The work is formalised through a series of Coloured Petri Nets and validated using two exemplary studies: one involving a structured business environment and the other a more creative setting. It has been deployed as a discrete service for the well-known, open-source workflow environment YAWL, and, having a service orientation, its applicability is in no way limited to that environment, but may be regarded as a case study in service-oriented computing whereby dynamic flexibility and exception handling for workflows, orthogonal to the underlying workflow language, is provided. Also, being open-source, it is freely available for use and extension.

Workflow systems aim to provide automated support for the conduct of certain business processes. Workflow systems are driven by workflow specifications which among others, capture the execution interdependencies between various activities. These interdependencies are modelled by means of different control flow constructors, e.g., sequence, choice, parallelism and synchronisation. It has been shown in the research on workflow patterns that the support for and the interpretation of various control flow constructs varies substantially across workflow systems. Two of the most problematic patterns relate to the OR-join and to cancellation. An OR-join is used in situations when we need to model " wait and see" behaviour for synchronisation. Different approaches assign a different (often only intuitive) semantics to this type of join, though they do share the common theme that synchronisation is only to be performed for active paths. Depending on context assumptions this behaviour may be relatively easy to deal with, though in general its semantics is complicated, both from a definition point of view (in terms of formally capturing a desired intuitive semantics) and from a computational point of view (how does one determine whether an OR-join is enabled?). Many systems and languages struggle with the semantics and implementation of the OR-join because its non-local semantics require a synchronisation depending on an analysis of future execution paths. This may require some non-trivial reasoning. The presence of cancellation features and other OR-joins in a workflow further complicates the formal semantics of the OR-join. The cancellation feature is commonly used to model external events that can change the behaviour of a running workflow. It can be used to either disable activities in certain parts of a workflow or to stop currently running activities. Even though it is possible to cancel activities in workflow systems using some sort of abort function, many workflow systems do not provide direct support for this feature in the workflow language. Sometimes, cancellation affects only a selected part of a workflow and other activities can continue after performing a cancellation action. As cancellation occurs naturally in business scenarios, comprehensive support in a workflow language is desirable. We take on the challenge of providing formal semantics, verification techniques as well as an implementation for workflows with those features. This thesis addresses three interrelated issues for workflows with cancellation regions and OR-joins. The concept of the OR-join is examined in detail in the context of the workflow language YAWL, a powerful workflow language designed to support a collection of workflow patterns and inspired by Petri nets. The OR-join semantics has been redesigned to represent a general, formal, and decidable approach for workflows in the presence of cancellation regions and other OR-joins. This approach exploits a link that is proposed between YAWL and reset nets, a variant of Petri nets with a special type of arc that can remove all tokens from a place. Next, we explore verification techniques for workflows with cancellation regions and OR-joins. Four structural properties have been identified and a verification approach that exploits coverability and reachability notions from reset nets has been proposed. The work on verification techniques has highlighted potential problems with calculating state spaces for large workflows. Applying reduction rules before carrying out verification can decrease the size of the problem by cutting down the size of the workflow that needs to be examined while preserving some essential properties. Therefore, we have extended the work on verification by proposing reduction rules for reset nets and for YAWL nets with and without OR-joins. The proposed OR-join semantics as well as the proposed verification approach have been implemented in the YAWL environment.

Over the past decade, the ubiquity of business processes and their need for ongoing management in the same manner as other corporate assets has been recognized through the establishment of a dedicated research area: Business Process Management (or BPM). There are a wide range of potential software technologies on which a BPM o®ering can be founded. Although there is signi¯cant variation between these alternatives, they all share one common factor { their execution occurs on the basis of a business process model { and consequently, this ¯eld of technologies can be termed Process-Aware Information Systems (or PAIS). This thesis develops a conceptual foundation for PAIS based on the results of a detailed examination of contemporary o®erings including work°ow and case han- dling systems, business process modelling languages and web service composition languages. This foundation is based on 126 patterns that identify recurrent core constructs in the control-°ow, data and resource perspectives of PAIS. These patterns have been used to evaluate some of the leading systems and business process modelling languages. It also proposes a generic graphical language for de¯ning exception handling strategies that span these perspectives. On the basis of these insights, a comprehensive reference language { newYAWL { is developed for business process modelling and enactment. This language is formally de¯ned and an abstract syntax and operational semantics are provided for it. An assessment of its capabilities is provided through a comprehensive patterns-based analysis which allows direct comparison of its functionality with other PAIS. newYAWL serves as a reference language and many of the ideas embodied within it are also applicable to existing languages and systems. The ultimate goal of both the patterns and newYAWL is to improve the support and applicability of PAIS.