Jaeyong Shim

A framework supporting dynamic workflow interoperation and enterprise application integration

In this paper, we propose a framework supporting dynamic interoperation between heterogeneous workflow systems and workflow-based dynamic enterprise application integration (EAI). To this end, based on a subflow task model and multi-tiered dynamic state transition model, four major components are defined: the workflow engine, adapter, service interface repositories (SIRs), and XML messages. The workflow engine provides a user with location transparency of subprocesses by encapsulating and dynamically binding both internal and external subprocesses. As middleware, the adapter achieves location and system transparency with the help of the workflow engine by encapsulating and dynamically binding external subprocesses to its superprocess. SIRs contain the service information of other systems. The local SIR (LSIR) within an organization is an important component for dynamic EAI. The adapter looks up the LSIR at run time when it tries to find external services. Several XML messages enable communications between heterogeneous workflow systems and enterprise applications.

Connector-oriented workflow system for the support of structured ad hoc workflow

In large scale enterprises composed of more than several hundred departments, many workflows still remain in a non-automated state which is a serious burden to the enterprises. Usually workflow of a large scale enterprise is in the mixed form of multiple types of workflow where ad hoc workflow is the major hurdle for the automation. While conventional workflow systems support a certain type of workflow well, it does not get along with a mixed type of workflow. We classify ad hoc workflow into structured and inherently ad hoc workflow and propose a workflow system equipped with a connector facility to support structured ad hoc workflow such as a decision approval process. The connector facility can be regarded as a semi-workflow system to support structured ad hoc workflow effectively or it can be a subsidiary facility for a workflow system to enforce the support of the structured ad hoc workflow in the base workflow system. We are implementing it in Hanuri/TFlow, our distributed transactional workflow system and the details of the connector-oriented extensions to the system are described.

Set-based access conflict analysis of concurrent workflow definition

An error-comprising workflow definition might provoke serious problems to an enterprise especially when it is involved with mission critical business processes. Concurrency of workflow processes is known as one of the major sources causing such an invalid workflow process definition. So the conflicts caused by concurrent workflow processes should be considered deliberately when defining concurrent workflow processes. If we can analyze the conflicts immanent in concurrent workflow definition prior to runtime, it will be very helpful to business process designers and many other users of workflow management systems. In this paper, we propose a set-based access conflict analysis method to detect all the possible access conflicts prior to the execution of the workflow process. The method is composed of two phases. In the first phase, it generates set constraints from a structured workflow definition. In the second phase, it solves the set constraints obtained from the first phase. Using the information about potential conflicts detected by our analysis, workflow designers can prevent the serious problems that can be raised by conflicts in runtime and they can convince whether their workflow definitions are free from such conflicts or not.

SET-BASED ANALYSIS OF STRUCTURED WORKFLOW DEFINITION

An error-comprising workflow definition of mission critical business process might incur serious problems to an enterprise. Although workflow designer is responsible for the error-comprising workflow definitions, workflow system has to be equipped with an intelligent workflow modeling tool preventing workflow designers from specifying error-comprising workflow definitions. Faults and mistakes of process designers have to be detected and reported to them by the tool at workflow build time. Access conflicts and improper specification of exceptions are two typical examples of such an error-comprising workflow definition. In this paper, we develop an access conflict detection and an uncaught exception detection techniques. A simple workflow definition language, named SWDL, is developed and the techniques are successfully developed on SWDL using Set Constraint System. With slight modifications and scope restrictions, the proposed techniques can be used in any workflow definition language either by translating it into SWDL or by referring to the techniques for the developing its own techniques. This indicates that general conventional programming language analysis techniques can be used in the analysis of workflow definitions by introducing an intermediate workflow definition language and developing analysis techniques on it.

Communication Deadlock Detection of Inter-organizational Workflow Definition

As the needs for interconnections of processes in different companies or departments are so increasing and companies try to realize business processes across organizational boundaries, the correctness issues of inter-organizational workflow definition is getting more important. In this paper, we develop community process definition language (CPDL) for inter-organizational workflow specification. It is devised to analyze correctness of inter-organizational workflow definition and especially it is used to detect latent communication deadlocks. A new communication deadlock detection technique in the context of interorganizational workflow definition is developed on CPDL using the set based constraint system. Any inter-organizational workflow languages that can be translated into CPDL can detect its communication deadlock using the technique of this paper.

Design and implementation of a distributed transactional workflow system

We designed a distributed transactional workflow system which supports multi-workflow types of large scale enterprises. The system aims to support the whole workflow of large scale enterprises effectively within a single workflow system and the system is designed to satisfy several interacting design goals such as availability, scalability and reliability. The transactional features of the system and the system architecture are also described in detail. Some characteristics of a workflow system can be made out by monitoring the system behavior on different conditions like workloads or system configurations. An early version of the system has been implemented and the performance data of the system is illustrated.

A framework supporting dynamic workflow interoperation

When a workflow process spans to multiple organizations, subprocess task model is an efficient way of representing remote services of other systems. The subprocess task usually represents a single service in conventional workflows. However, if a subprocess task comprises multiple services, and the number of services and the execution flow of the services cannot be decided until run-time, conventional ways of workflow design is not proper to handle such situations efficiently. All potentially reachable paths should be known at process build time in conventional workflow design. However, such an assumption does not always hold in real situations. In this paper, we propose a multi-subprocess task based framework for dynamic workflow interoperations. In the framework, we develop the multi-subprocess task model to handle a subprocess composed of multiple services that are unknown at process build time. In this paper, we also define and implement four components to support the dynamic workflow interoperation: Workflow engine, Adapter, Service Interface Repositories (SIRs), and XML messages. Adapter and SIR make a local WfMS transparent to the location and platform of the interoperating WfMSs by encapsulating external subprocesses and superprocesses. When an example scenario is implemented and evaluated in the proposed framework, the advantages of the framework are obvious in terms of automaticity, adaptability, and efficiency.