Abstract not found

Modern enterprises increasingly use the workflow paradigm to prescribe how business processes should be performed. Processes are typically modeled as annotated activity graphs. We present an approach for a system that constructs process models from logs of past, unstructured executions of the given process. The graph so produced conforms to the dependencies and past executions present in the log. By providing models that capture the previous executions of the process, this technique allows easier introduction of a workflow system and evaluation and evolution of existing process models. We also present results from applying the algorithm to synthetic data sets as well as process logs obtained from an IBM Flowmark installation.

Transaction management in shared databases is generally viewed as a combination of two problems, concurrency control and recovery, which have been considered as orthogonal problems. Consequently, the correctness criteria derived for these problems are incomparable. Recently a unified theory of concurrency control and recovery has been introduced that is based on commutativity and performs transaction recovery by submitting inverse operations for operations of aborted transactions. In this paper we provide a constructive correctness criterion that leads to the design of unified protocols that guarantee atomicity and serializability.

A workflow is an activity involving the coordinated execution of multiple tasks performed by different processing entities [KS95]. These tasks could be manual, or automated, either created specifically for the purpose of the workflow application being developed, or possibly already existing as legacy

Abstract. Work ow management is a ubiquitous task faced by many organizations, and entails the coordination of various activities. This coordination is increasingly carried out by software systems called workow management systems (WFMS). An important component ofmany WFMSs is a DBMS for keeping track ofwork ow activity. This DBMS maintains an audit trail, or event history, that records the results of each activity. Like other data, the event history can be indexed and queried, and views can be de ned on top of it. In addition, a WFMS must accommodate frequent work ow changes, which result from a rapidly evolving business environment. Since the database schema depends on the workow, the DBMS must also support dynamic schema evolution. These requirements are especially challenging in high-throughput WFMSs|i:e:, systems for managing high-volume, mission-critical work ows. Unfortunately, existing database benchmarks do not capture the combination of exibility and performance required by these systems. To address this issue,

Workflow management systems are finding wide applicability in small and large organizational settings. In this paper, we briefly review four large-scale applications to gauge their modeling and run-time requirements. Advanced transaction models (ATM) focus on maintaining data consistency and have provided solutions to many problems such as correctness, consistency, and reliability in transaction processing and database management environments. While such concepts have yet to be solved in the domain of workflow systems, database researchers have proposed to use, or attempted to use ATMs to model workflows. In this paper, we argue that workflow requirements in large-scale enterprise-wide applications involving heterogeneous and distributed environments far exceed the modeling and functionality support provided by ATMs, and suggest that an ATM is unlikely to provide a primary basis for workflow modeling and subsequent management. We have also presented various connotations of the term transaction that exist in the real-world organizational processes. Finally, we point out the need for looking beyond ATMs and using a multi-disciplinary approach for modeling large-scale workflow applications of the future.

Database management systems #DBMSs# have been increasingly used for advanced application domains# such as software development environments# network management# workflow management systems# computer-aided design and manufacturing# and managed healthcare. In these domains# the standard correctness model of serializability is often too restrictive. We introduce the notion of a Concurrency Control Language #CCL# that allows a database application designer to specify concurrency control policies to tailor the behavior of a transaction manager. A well-crafted set of policies defines an extended transaction model. The necessary semantic information required by the CCL run-time engine is extracted from a task manager# a #logical# module by de#nition included in all advanced applications. This module stores task models that encode the semantic information about the transactions submitted to the DBMS. We have designed a rule-based CCL# called cord# and have implemented a run-time engine that ca...

The workflow concept has been very successful in streamlining business processes by automating the coordination of activities, but has so far been limited to the use within single organizations. Any attempt to distribute workflows among different organizations has to face the problems posed by the complex relationship among autonomous organizations and their services. To address these problems we propose a service-oriented model for cross-organizational workflows. Modeling the workflow execution as a cooperation of services allows different organizations to interact via well-defined interfaces. We further show how the execution can be optimized by selecting services depending on their contribution to quality criteria of the workflow.

Exceptions are one of the most pervasive problems in process support systems. In installations expected to handle a large number of processes, having exceptions is bound to be a normal occurrence. Any programming tool intended for large, complex applications has to face this problem. However, current process support systems, despite their orientation towards complex, distributed, and heterogeneous applications, provide almost no support for exception handling. This paper shows how exible mechanisms for failure handling are incorporated into the OPERA process support system using a combination of programming language concepts and transaction processing techniques. The resulting mechanisms allow the construction of fault-tolerant work ow processes in a transparent and exible way while ensuring reusability ofwork ow components. 1

In this paper, we present a novel technique for modeling, checking, and enforcing temporal constraints in workflow processes containing conditionally executed activities. Existing workflow time modeling proposals either do not discriminate between time constraints that apply to disparate execution paths, or they treat every execution path independently. Consequently, superfluous time constraint violations may be detected at modeling time, even when each execution path does not violate any constraints. In addition, scheduling conflicts during process execution may not be detected for activities that are common to multiple execution paths. Our approach addresses these problems by (partially) unfolding the workflow graph associated with a process that contains conditionally executed activities and, then, incorporating the temporal constraints in the time calculations performed on the unfolded graph.