Evaluation of Correctness Criteria for Dynamic Workflow Changes

The capability to dynamically adapt in-progress workflows (WF) is an essential requirement for any workflow management system (WfMS). This fact has been recognized by the WF community for a long time and different approaches in the area of adaptive workflows have been developed so far. They either enable WF type changes and their propagation to in-progress WF instances or (ad-hoc) changes of single WF instances. Thus, at first glance, many of the major problems related to dynamic WF changes seem to be solved. However, this picture changes when digging deeper into the approaches and considering implementation and usability issues as well. This paper presents important criteria for the correct adaptation of runningw orkflows and analyzes how actual approaches satisfy them. At this, we demonstrate the strengths of the different approaches and provide additional solutions to overcome current limitations. These solutions comprise comprehensive correctness criteria as well as migration rules for change realization

Change Support in Process-Aware Information Systems - A Pattern-Based Analysis

In today's dynamic business world the economic success of an enterprise increasingly depends on its ability to react to changes in its environment in a quick and flexible way. Process-aware information systems (PAIS) offer promising perspectives in this respect and are increasingly employed for operationally supporting business processes. To provide effective business process support, flexible PAIS are needed which do not freeze existing business processes, but allow for loosely specified processes, which can be detailed during run-time. In addition, PAIS should enable authorized users to flexibly deviate from the predefined processes if required (e.g., by allowing them to dynamically add, delete, or move process activities) and to evolve business processes over time. At the same time PAIS must ensure consistency and robustness. The emergence of different process support paradigms and the lack of methods for comparing existing change approaches have made it difficult for PAIS engineers to choose the adequate technology. In this paper we suggest a set of changes patterns and change support features to foster the systematic comparison of existing process management technology with respect to process change support. Based on these change patterns and features, we provide a detailed analysis and evaluation of selected systems from both academia and industry. The identified change patterns and change support features facilitate the comparison of change support frameworks, and consequently will support PAIS engineers in selecting the right technology for realizing flexible PAIS. In addition, this work can be used as a reference for implementing more flexible PAIS

Identifying and Evaluating Change Patterns and Change Support Features in Process-Aware Information Systems.

In order to provide effective support, the introduction of process-aware information systems (PAIS) must not freeze existing business processes. Instead PAIS should allow authorized users to flexibly deviate from the predefined processes if required and to evolve business processes in a controlled manner over time. Many software vendors promise flexible system solutions for realizing such adaptive PAIS, but are often unable to cope with fundamental issues elated to process change (e.g., correctness and robustness). The existence of different process support paradigms and the lack of methods for comparing existing change approaches makes it difficult for PAIS engineers to choose the adequate technology. In this paper we suggest a set of changes patterns and change support features to foster systematic comparison of existing process management technology with respect to change support. Based on these change patterns and features, we provide a detailed analysis and evaluation of selected systems from both academia and industry

Dealing with Forward and Backward Jumps in Workflow Management Systems

Workflow management systems (WfMS) offer a promising technology for the realization of process-centered application systems. Adeficiency of existingWfMSis their inadequate support for dealing with exceptional deviations from the standard procedure. In the ADEPT project, therefore, we have developed advanced concepts for workflow modeling and execution, which aim at the increase of flexibility in WfMS. On the one hand we allow workflow designers to model exceptional execution paths already at buildtime provided that these deviations are known in advance. On the other hand authorized users may dynamically deviate from the pre-modeled workflowat runtime as well in order to deal with unforeseen events. In this paper, we focus on forward and backward jumps needed in this context. We describe sophisticated modeling concepts for capturing deviations in workflow models already at buildtime, and we show how forward and backward jumps (of different semantics) can be correctly applied in an ad-hoc manner during runtime as well. We work out basic requirements, facilities, and limitations arising in this context. Our experiences with applications from different domains have shown that the developed concepts will form a key part of process flexibility in process-centered information systems

Enabling Flexibility in Process-Aware Information Systems: Challenges, Methods, Technologies

In today’s dynamic business world, the success of a company increasingly depends on its ability to react to changes in its environment in a quick and flexible way. Companies have therefore identified process agility as a competitive advantage to address business trends like increasing product and service variability or faster time to market, and to ensure business IT alignment. Along this trend, a new generation of information systems has emerged—so-called process-aware information systems (PAIS), like workflow management systems, case handling tools, and service orchestration engines. With this book, Reichert and Weber address these flexibility needs and provide an overview of PAIS with a strong focus on methods and technologies fostering flexibility for all phases of the process lifecycle (i.e., modeling, configuration, execution and evolution). Their presentation is divided into six parts. Part I starts with an introduction of fundamental PAIS concepts and establishes the context of process flexibility in the light of practical scenarios. Part II focuses on flexibility support for pre-specified processes, the currently predominant paradigm in the field of business process management (BPM). Part III details flexibility support for loosely specified processes, which only partially specify the process model at build-time, while decisions regarding the exact specification of certain model parts are deferred to the run-time. Part IV deals with user- and data-driven processes, which aim at a tight integration of processes and data, and hence enable an increased flexibility compared to traditional PAIS. Part V introduces existing technologies and systems for the realization of a flexible PAIS. Finally, Part VI summarizes the main ideas of this book and gives an outlook on advanced flexibility issues. The attached pdf file gives a preview on Chapter 3 of the book which explains the book's overall structure

An Approach for Supporting Ad-hoc Modifications in Distributed Workflow Management Systems

Supporting enterprise-wide or even cross-organizational business processes is a characteristic challenge for any workflow management system (WfMS). Scalability at the presence of high loads as well as the capability to dynamically modify running workflow (WF) instances (e.g., to cope with exceptional situations) are essential requirements in this context. Should the latter one, in particular, not be met, the WfMS will not have the necessary flexibility to cover the wide range of process-oriented applications deployed in many organizations. Scalability and flexibility have, for the most part, been treated separately in the relevant literature thus far. Even though they are basic needs for a WfMS, the requirements related with them are totally different. To achieve satisfactory scalability, on the one hand, the system needs to be designed such that a workflow instance can be controlled by several WF servers that are as independent from each other as possible. Yet dynamic WF modifications, on the other hand, necessitate a (logical) central control instance which knows the current and global state of a WF instance. For the first time, this paper presents methods which allow ad-hoc modifications (e.g., to insert, delete, or shift steps) to be performed in a distributed WfMS; i.e., in a WfMS with partitioned WF execution graphs and distributed WF control. It is especially noteworthy that the system succeeds in realizing the full functionality as given in the central case while, at the same time, achieving extremely favorable behavior with respect to communication costs