Requirements for the workflow-based support of release management processes in the automotive sector

One of the challenges the automotive industry currently has to master is the complexity of the electrical/elctronic system of a car. One key factor for reaching short product development cycles and high quality in this area are well-defined, properly executed test and release processes. In this paper we show why workflow management technology is needed to support these processes and how this support should look like. We further confront these requirements with the features of contemporary workflow technology and discuss which extensions become necessary

Survivor: An Approach for Adding Dependability to Legacy Workflow Systems

Although they often provide critical services, most workflow systems are not dependable. There has been much literature on dependable/survivable distributed systems; most is concerned with developing new architectures, not adapting pre-existing ones. Additionally, the literature is focused on hardening, security-based defense, as opposed to recovery. For deployed systems, it is often infeasible to completely replace existing infrastructures; what is more pragmatic are ways in which existing distributed systems can be adapted to offer better dependability. In this paper, we outline a general architecture that can easily be retrofitted to legacy workflow systems in order to improve dependability and fault tolerance. We do this by monitoring enactment and replicating partial workflow states as tools for detection, analysis and recovery. We discuss some policies that can guide these mechanisms. Finally, we describe and evaluate our implementation, Survivor, which modified an existing workflow system provided by the Naval Research Lab

Entangled queries: enabling declarative data-driven coordination

Many data-driven social and Web applications involve collaboration and coordination. The vision of Declarative Data-Driven Coordination (D3C), proposed in Kot et al. [2010], is to support coordination in the spirit of data management: to make it data-centric and to specify it using convenient declarative languages. This article introduces entangled queries, a language that extends SQL by constraints that allow for the coordinated choice of result tuples across queries originating from different users or applications. It is nontrivial to define a declarative coordination formalism without arriving at the general (NP-complete) Constraint Satisfaction Problem from AI. In this article, we propose an efficiently enforceable syntactic safety condition that we argue is at the sweet spot where interesting declarative power meets applicability in large-scale data management systems and applications. The key computational problem of D3C is to match entangled queries to achieve coordination. We present an efficient matching algorithm which statically analyzes query workloads and merges coordinating entangled queries into compound SQL queries. These can be sent to a standard database system and return only coordinated results. We present the overall architecture of an implemented system that contains our evaluation algorithm. We also describe a proof-of-concept Facebook application we have built on top of this system to allow friends to coordinate flight plans. Finally, we evaluate the performance of the matching algorithm experimentally on realistic coordination workloads

Enterprise-wide and Cross-enterprise Workflow Management: Concepts, Systems, Applications

These proceedings comprise a number of papers on issues related to cross-organizational workflow management

Failure handling and coordinated execution of concurrent workflows

Workflow management systems (WFMSs) coordinate the execution of applications distributed over networks. In WFMSs, data inconsistencies can arise due to: the interaction between steps of concurrent threads within a workflow (intra-workflow coordination); the interaction between steps of concurrent workflows (inter-workflow coordination); and 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 new requirements for workflow executions and implemented a run-time system for managing workflow executions while satisfying the new requirements. These ideas are geared towards improving the modeling and correctness properties offered by WFMSs and making them more robust and flexibl

Supporting effective unexpected exception handling in workflow management systems within organizaional contexts

Tese de doutoramento em Informática (Engenharia Informática), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008Workflow Management Systems (WfMS) support the execution of organizational processes within organizations. Processes are modelled using high level languages specifying the sequence of tasks the organization has to perform. However, organizational processes do not have always a smooth flow conforming to any possible designed model and exceptions to the rule happen often. Organizations require flexibility to react to situations not predicted in the model. The required flexibility should be complemented with robustness to guarantee system reliability even in extreme situations. In our work, we have introduced the concept of WfMS resilience that comprises these two facets: robustness and flexibility. The main objective of our work is to increase resilience in WfMSs. From the events demanding for WfMS resilience, we focused on ad hoc effective unexpected exceptions as those for which no previous knowledge exist is the organization to derive the handling procedure and no plan can be a priori established. These exceptions usually require human intervention and problem solving activities, since the concrete situation may not be entirely understood before humans start reacting to the event. After discussing existing approaches to increase WfMS resilience, we have identified five levels of conformity. The fifth level, being the most demanding one, requires unrestricted humanistic interventions to workflow execution. In this thesis, we propose a system to support unrestricted users' interventions to the WfMS and we characterize the interventions as unstructured activities. The system has two modes of operation: it usually works under model control and changes to unstructured activities support when an exception is detected. The exception handling activities are carried out until the system is placed back into a coherent mode, where work may proceed undermodel execution control