this paper may be "long running" or not. Other related terms used in the database literature are task flow, multitransaction activities [7], multi-system applications [1], application multiactivities, and networked applications [4]. Some related issues are also addressed in various relaxed transaction models.

Workflow management systems (WFMSs) more and more become the basic technology for organizations to perform their daily business processes (workflows). A consistent and reliable execution of such processes is crucial for all organizations. We claim that this can only be achieved by integrating transactional features - especially "workflow transactions " - into WFMSs. Based on this idea, we discuss in detail advanced workflow recovery concepts which are necessary for the reliable and consistent execution of business processes in the presence of failures and exceptions. Additionally, we distinguish between different workflow types and present adequate recovery concepts for each of them. 1.

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

Workflow management systems (WFMSs) coordinate the execution of applications distributed over networks. In WFMSs, data inconsistencies can arise due to (i) the interaction between steps of concurrent threads within a workflow (intra-workflow coordination) (ii) the interaction between steps of concurrent workflows (interworkflow coordination) and (iii) the presence of failures. Since these problems have not received adequate attention, this paper focuses on developing the necessary concepts and infrastructure to handle them. First, to deal with inter- and intra- workflow coordination requirements we have identified a set of high level building blocks. Secondly, to handle failures we propose a novel and pragmatic approach called opportunistic compensation and re-execution that allows a workflow designer to customize workflow recovery from correctness as well as performance perspectives. Thirdly, based on these concepts we have designed a workflow specification language that expresses ne...

If the number of users within a workflow management system (WFMS) increases, a central workflow server (WF-- server) and a single local area network (LAN) may become overloaded. The approach presented in this paper describes an execution environment which is able to manage a growing number of users by adding new servers and subnets. The basic idea is to decompose processes into parts which are controlled by different WF--servers. That is, during the execution of a workflow instance its execution (step) control may migrate from one WF--server to another. By selecting the appropriate physical servers (for hosting the WF--servers) in the appropriate LANs, communication costs and individual WF--server workload can be reduced significantly. 1. Introduction Since a couple of years there has been a growing interest in using WFMS for implementing process--oriented application systems. As the benefit of such application systems increases with the number of applications being served, the number...

On the Dutch workflow market a new and interesting paradigm named "case handling" is emerging. The goal of case handling is to overcome the limitations of existing workflow management systems. By using a data-driven approach combined with implicit routing and carefully avoiding context tunneling, awareness and flexibility are improved. Currently, many organizations are considering case handling systems such as FLOWer (Pallas Athena) rather than the more traditional workflow management systems. This paper provides a critical assessment of this development. The goal is to show the pro's and con's of case handling. Moreover, based on this assessment an alternative approach using slightly extended traditional workflow management systems is proposed. This approach is being pursued by the Dutch governmental agency CJIB in a project involving the workflow management system Staffware. Based on our experiences thus far, we provide guidelines for selecting the proper technology.

. Workflow Management is a technique to integrate and automate the execution of steps that comprise a complex process, e:g:; a business process. Workflow Management Systems (WFMSs) primarily evolved from industry to cater to the growing demand for office automation tools among businesses. Coincidentally, database researchers developed several extended transaction models to handle similar applications. Although the goals of both the communities were the same, the issues they focused on were different. The workflow community primarily focused on modeling aspects to accurately capture the data and control flow requirements between the steps that comprise a workflow, while the database community focused on correctness aspects to ensure data consistency of sub-transactions that comprise a transaction. However, we now see a confluence of some of the ideas, with additional features being gradually offered by WFMSs. This paper provides an overview of correctness in workflow management. Correct...

Abstract. For enterprise-wide and cross-enterprise workflow (WF) applications, the load of the WF servers and the amount of communication in the subnets may become a bottleneck. This paper shows how a distributed WF control can be realized in a way that the load of the components at run time is minimized. For that purpose, the control of a WF instance may migrate from one WF server to another. The WF servers are assigned to the WF activities in a way that minimizes the communication load. The server assignments are determined at build time by analyzing the WF model with respect to the actor assignments. As these actor assignments may depend on preceding activities, static server assignments are not always reasonable. Hence, so-called variable server assignment expressions are introduced, which allow dynamic server assignment without expensive run time analyses. 1

Abstract. Handling workflow transactional behavior remains a main problem to ensure a correct and reliable execution. It is obvious that the discovery, and the explanation of this behavior, would enable to better understand and control workflow recovery. Unfortunately, previous workflow mining works have concentrated their efforts on control flow aspects. Although powerful, these proposals are found lacking in functionalities and performance when used to discover workflow transactional behavior. In this paper, we describe mining techniques, which are able to discover a workflow model, and to improve its transactional behavior from event based logs. First, we propose an algorithm to discover workflow patterns. Then, we propose techniques to discover activities transactional dependencies that allow us to mine workflow recovery techniques. Finally, based on this mining step, we use a set of rules to improve workflow design.

Process Support Systems (PSSs) are software systems supporting the modeling, enactment, monitoring, and analysis of business processes. Process automation technology can be fully exploited when predictable and repetitive processes are executed. Unfortunately, many processes are faced with the need of managing exceptional situations that may occur during their execution, and possibly even more exceptions and failures can occur when the process execution is supported by a PSS. Exceptional situations may be caused by system (hardware or software) failures, or may by related to the semantics of the business process.