Mati Golani

Flexible business process management using forward stepping and alternative paths

The abilty to continuously revise business practices is essential to organizations aiming at reducing their costs and increasing their revenues. Rapid and continuous changes to business processes result in less control over the executed activities. As a result, the ability of process designers to produce solid, well-validated workflow models is limited. Workflow management systems (WfMSs), serving as the main vehicle of business process execution, should recognize these risks and become more dynamic to allow the required business flexibility. In this paper, we propose a dynamic mechanism that allows backtracking and forward stepping at an instance level. This mechanism analyzes the feasibility of applying certain modifications to running instances and provides an efficient algorithm that avoids redundant operation activation. We believe that this mechanism can bolster the ability of a business process management system to deal with unexpected situations and to resolve, in runtime, scenarios in which such resolution both is called for and does not violate any business process constraints. Throughout this paper, we use the paradigm of Web services to demonstrate the capabilities of the proposed mechanism.

Optimizing exception handling in workflows using process restructuring

Exception handling is the process by which a failure in a process is mitigated. Depending on the specifics of an exception, exception handers – specifications of exception handling processes – may range from halting a process, through attempts of activity reactivation, to an identification of an alternative path to successful completion of a process. Designing efficient exception handlers is not a simple task. By their very nature, exceptions are rare events that may result in poor design of exception handlers in terms of cost and logic. In this work we aim at improving exception handling performance in workflow management systems (WfMSs), a task which has been recognized as a fundamental component of WfMSs that is critical to their successful deployment in real-world scenarios. Our approach is based on the observation that when designing a business process as a workflow, a designer has some degree of freedom in streamlining actions. Therefore, we propose process model restructuring as a main tool in reducing the cost of exception handling. We believe that restructuring of a process model, based on exception efficiency consideration, can increase the overall productivity of the business process. Although the rarity of exceptions allows amortizing their costs over time we cannot ignore exception costs altogether. Therefore, we propose a cost-based approach to prioritize their impact on the workflow design. Our main contribution is the provision of a methodology for exception handling optimization at the workflow design phase.

Modeling alternatives in exception executions

To date, the ability of a business process designer to produce a solid, well-validated workflow models is limited, especially since all necessary scenarios that need to be covered by the workflow are hard to predict. Workflow management systems (WfMSs), serving as the main vehicle of business process execution, should recognize those limits, and increase its support to designers in this task. One aspect of such assistance is in exception handlers generation. In this paper we propose a model language enrichment for expressing workflow semantics, in the context of alternative solutions, within the process model. Thus, enabling the designer to state which possible alternatives and their applicability to changing execution paths states. Using this enrichment, an inference algorithm can efficiently find an adequate alternative. The model language is used as a basis for a design tool and an execution environment, which semi-automatically generates exception handlers, resulting, due to a reduced search space, in a smaller set of exceptions for the designer/user to choose from.

Temporal Active Rules

Many rule-base applications are required to support evolving behavior. This may be expressed using evolving rules. This paper describes a framework for the definition and use of temporal ECA rules. This framework supports: rule versions that may be simultaneously applicable, the selection of a rule among several alternatives, and flexible rules in decision support systems that employ hypothetical scenarios. This paper presents and discusses several temporal models (transaction time model, valid time model and bi-temporal model) of rules, and their application to various types of databases. It presents an execution model that allows the system designer to select rules according to filters whenever different versions of rules may apply. This capability is vital for applications such as: rule evolution in an environment that allows retroactive update (E.g. tax system) and in decision support systems that manage hypothetical scenarios based on rules.

Workflow Reconfiguration Using Chains

Work.ows have become a common tool for modeling organizational activities. Research and practice of Work.ow Management Systems (WfMS) involve ontological aspects (e.g., the relevant constructs for modeling inter-organizational work.ows [2,1]), design aspects (e.g., synchronization of concurrent work.ow instances [4]), reverse engineering [3], and optimization. The latter has seen few advances, especially when it comes to dynamic work.ow design, where organizations need to continuously revise their work.ows. As an illustrative example, consider virtual enterprises, enterprises that are formed in a competitive market to respond to the need to improve cost/performance ratio by cross-organizational cooperation. Cross-organizational operations require a dynamic .exible mechanism that can handle the data .ow among di.erent partners [5,6]. Therefore, if one partner delivers raw material to another partner for further processing, then whenever one partner changes the characteristics of the raw material (either a temporary or a permanent change) it should be re.ected in the business process of the other (e.g., machinery replacement). In environments that require fast response, an o.-line update procedure decreases the e.ciency of the organization and may cause unnecessary delays due to the need to restart the work.ow engine with any new change. Therefore, an optimized process, involving online recon.guration and .exible resource allocation, becomes an important feature of work.ow management.