Workflow Schema Research Articles

E-MEMO: Referenzmodelle zur ökonomischen Realisierung leistungsfähiger Infrastrukturen für Electronic Commerce

For many companies, the development of a competitive E-Commerce strategy and even more so its implementation is a huge challenge. This paper presents a method that is aimed at reducing substantially cost and risk of such an endeavour. The method has been adapted from an existing method for multi-perspective enterprise modelling. It supports strategy analysis and design as well as the corresponding organisational design. It also fosters the configuration of supporting information systems. Besides specialized process models, the method offers reference models for strategy design and a library of business process models. The process models can be transformed automatically into workflow schemata.

Extracting the workflow critical path from the extended well-formed workflow schema

The critical path in a workflow schema is defined as the longest execution path from the start activity to the end activity. It can be utilized in many workflow issues such as workflow resource and time management. However, little work has been done on the critical path in a workflow because workflow control flows are much more complex than those represented with ordinary graphs and networks. In this paper, we first describe our workflow model with a set of workflow control constructs that provide sufficient power to express the models of most of today's business processes. Then, we propose a systematic method of identifying the critical path for a given workflow schema. Our proposed method is based on queuing theory because operational characteristics of the workflow schema can be modeled by a M/M/1 queuing network.

Flexible Support of Team Processes by Adaptive Workflow Systems

Process-oriented support of collaborative work is an important challenge today. At first glance, Workflow Management Systems (WfMS) seem to be very suitable tools for realizing team-work processes. However, such processes have to be frequently adapted, e.g., due to process optimizations or when process goals change. Unfortunately, runtime adaptability still seems to be an unsolvable problem for almost all existing WfMS. Usually, process changes can be accomplished by modifying a corresponding (graphical) workflow (WF) schema. Especially for long-running processes, however, it is extremely important that such changes can be propagated to already running WF instances as well, but without causing inconsistencies and errors. The paper presents a general and comprehensive correctness criterion for ensuring compliance of in-progress WF instances with a modified WF schema. For different kinds of WF schema changes, it is precisely stated, which rules and which information are needed at mininum for satisfying this criterion.

Flexible Composition of Enterprise Web Services

The process-based composition of Web services is emerging as a promising approach to automate business process within and across organizational boundaries. In this approach, individual Web services are federated into composite Web services whose business logic is expressed as a process model. Business process automation technology such as workflow management systems (WFMSs) can be used to choreograph the component services. However, one of the fundamental assumptions of most WFMSs is that workflow schemas are static and predefined. Such an assumption is impractical for business processes that have an explosive number of options, or dynamic business processes that must be generated and altered on the fly to meet rapid changing business conditions. In this paper, we describe a rule inference framework called DY flow , where end users declaratively define their business objectives or goals and the system dynamically composes Web services

An environment for designing exceptions in workflows

When designing a workflow schema, the workflow designer must often explicitly deal with exceptional situations, such as abnormal process termination or suspension of task execution. This paper shows how the designer can be supported by tools allowing him to capture exceptional behavior within a workflow schema, by reusing an available set of pre-configured exceptions skeletons. Exceptions are expressed by means of triggers, to be executed on the top of an active database environment. In particular, the paper deals with the handling of typical workflow exceptional situations which are modeled as generic exception skeletons to be included in a new workflow schema by simply specializing or instantiating them. Such skeletons, called patterns, are stored in a catalog; the paper describes the catalog structure and its management tools constituting an integrated environment for pattern-based exception design and reuse.

WIDE workflow development methodology

The development of workflows (WFs) for complex organizations to be interfaced with existing information systems requires a specific methodological approach to guarantee benefits and effectiveness of the final results. In fact, the WF should be well integrated in the organization both from the technical and the organizational point of view. While the characteristics of the Workflow Management System (WFMS) platform adopted in the implementation are relevant to establish the boundary between the workflow system and other related applications, it is also important that the analysis and design phases are developed independently of those characteristics.The WF development methodology proposed in this paper starts with an analysis phase based on UML, adopted for business process descriptions and business goals. The design phase proposes a pattern-based approach to workflow schemas design, based on the WIDE WF model. This model allows a flexible representation of the exceptions which may occur during WF execution. It also considers the interaction of the WF with external applications and information systems. Finally, the paper briefly discusses the mapping to commercial and prototype WFMSs.

Workflow evolution

A basic step towards flexibility in workflow systems is the consistent and effective management of workflow evolution, i.e. of changing existing workflows while they are operational. One of the most challenging issue is the handling of running instances when their schemata are modified: simple solutions can be devised, but they often imply losing all the work done or failing in capturing the advantages offered by workflow modifications; this is unacceptable for many applications. In this paper we address the problem of workflow evolution, from both a static and a dynamic point of view. We define a complete, minimal, and consistent set of modification primitives that allow modifications of workflow schemata and we introduce a taxonomy of policies to manage evolution of running instances when the corresponding workflow schema is modified. Formal criteria are introduced, based on a simple workflow conceptual model, in order to determine which running instances can be transparently migrated to the new version. A case study, relating the assembling of a desktop computer, will exemplify the introduced concepts.