Simple temporal networks with uncertainty (STNUs) have achieved wide attention and are the basis of many applications requiring the representation of temporal constraints and checking whether they are conflicting. Dynamic controllability is currently the most studied notion to check whether a system can be controlled without violating temporal constraints despite uncertainties. However, dynamic controllability assumes that the actual duration of a contingent activity is known only when the end event of that activity occurs. The recently introduced notion of agile controllability considers the case where this duration is known earlier, leading to a more relaxed notion of temporal feasibility. We extend the definition of STNUs to STNUOs (Simple Temporal Networks with Uncertainty and Oracles) to represent the point in time at which information about a contingent duration is available. We formally define agile controllability as a generalization of dynamic controllability considering the timepoints of information availability. We propose a set of constraint propagation rules for STNUOs, leading to an algorithm for checking agile controllability.

Cross-organizational business processes emerge from the cooperation of intra-organizational business processes exchanging messages. The cooperating processes establish temporal agreements in the form of constraints, representing timeliness obligations on the one hand and guarantees on the other hand. These constraints also form requirements for the design of the hidden implementation of the processes and are the basis of local control decisions. We present a comprehensive methodology for modeling the temporal aspects of cross-organizational business processes, checking the dynamic controllability of such processes, and supporting the reaching and the checking of temporal agreements. We do so by computing the consequences of temporal constraints and business secrecy requirements and by computing the weakest preconditions for the dynamic controllability of a participating process.

Web service compositions establish Temporal Service Level Agreements to have guarantees of temporal correctness. Temporal SLAs can be realized through the exchange of temporal parameters between service providers and clients. However, so far, it was not possible to compute a priori restrictions on the values for these parameters, such that the composition is dynamically controllable, i.e. free from time failures under any foreseeable circumstance. Here we provide a sound and complete method to compute restrictions for temporal parameters in a Web service composition with guarantees of dynamic controllability.

Processes have been successfully introduced for modeling dynamic phenomena in many areas like business, production, health care, etc. Many of these applications require to adequately deal with temporal aspects. Process models need to express temporal durations, temporal constraints like allowed time between events, and deadlines. For checking the correctness of process definitions with temporal constraints, different notions and algorithms have been developed. Schedules for the execution of processes can be computed and proactive time management supports process managers to avoid time failures during the execution of a process. We present an overview of the problems and the requirements for treating time in business processes and the solutions achieved by applying results and techniques of research in temporal representation and reasoning. We reflect where expectations have not yet been met and sketch challenges in temporal representation and reasoning for addressing advanced requirements of the management of business processes.

Cross-organizational business processes emerge from the cooperation of intra-organizational business processes through exchange of messages. The involved parties agree on communication protocols, which contain in particular temporal constraints: as obligations on one hand, and as guarantees on the other hand. These constraints form also requirements for the design of the hidden implementation of the processes and are the basis for control decisions for each party. We present a comprehensive methodology for modeling the temporal aspects of cross-organizational business processes, checking dynamic controllability of such processes, and supporting the negotiation of temporal commitments. We do so by computing the consequences of temporal constraints in choreographies, and by computing the weakest preconditions for the dynamic controllability of a participating process.

Temporal Service Level Agreements are an important quality criterion for the offering of composed web services. The formulation of temporal requirements of a service might involve parameters passed to the service. We propose a technique enabling service providers to check whether they can guarantee a temporal service level agreement (SLA) requested by a client. This techniques is based on analyzing the controllability of service compositions with temporal parameters taking into account range constraints on these parameters as specified in a temporal SLA.

Temporal Service Level Agreements (SLAs) are a distinguishing characteristics for offered (composed) services: the weaker the restrictions, the broader the ranges of input parameters, the wider the applicability of an offered service. We propose a technique for the providers of composed services with temporal parameters to compute the broadest ranges for the temporal input parameters such that all service invocations where the parameters are within these ranges are dynamically controllable, i.e. that the adherence to temporal constraints can be guaranteed.

Inter-organizational business processes can be designed top-down: starting from a global process model, where each activity and gateway is assigned to one of the participating organizations, local processes (or views/stubs for refinement) are generated for each organization. The resulting inter-organizational process is executed by the local processes in a fully distributed manner. Implementing the data-flow in such a scenario is highly complex, both because of the combinatorial explosion of possible solutions and because of conflicting goals for implementing the data-flow. We present a flexible, heuristic algorithm for implementing the data-flow for inter-organizational processes according to various user preferences, which significantly improves over the base-line approaches proposed so far. The approach is fully implemented and a comprehensive, multi-dimensional evaluation is provided.

The composition of web services frequently requires the adequate representation of temporal requirements, temporal obligations, and temporal assumptions. Currently, the modeling of orchestrations and their service level agreements including temporal constraints suffers however from a mismatch between more procedural orchestration models and more declarative formulations of temporal constraints. We proposed the introduction of temporal conditions in the formulation of conditional constructs for process modeling to give process designers explicit control over the temporal behavior of the processes they model. By transforming the so modeled processes to processes with decision nodes we can take advantage of the recently developed CSTNUDs, temporal control networks with conditions, uncertainty and decisions, which in particular provide for checking the dynamic controllability of temporally constrained processes.

We introduce an extension to the declarative and artifact-centric Guard Stage Milestone (GSM) process modeling language to represent temporal aspects (duration, deadlines, lower- and upper-bound constraints), define the correctness of executions of GSM processes with respect to temporal constraints, check controllability of processes, compute execution plans respecting temporal constraints, and provide a translation method allowing to execute controllable GSM+T processes on standard GSM Engines.

Inter-organizational business processes can be designed top-down following the public to private approach. First, a global process model is designed. In a second step, each activity is assigned to one of the business partners. Finally, processes (or views/stubs for refinement) are generated for each partner. The resulting inter-organizational process is executed in a fully distributed way by the set of communicating local processes. Existing approaches concentrate on the control-flow and ignore the data-flow or follow rather simple approaches for implementing the data-flow. However, automatically generating message-exchanges is a challenging task since numerous solutions with hugely varying advantages and disadvantages are possible. In this paper, we present criteria for assessing data-flow implementation and discuss baseline approaches that each optimize one of these criteria. All algorithms are implemented and evaluated for a variety of different process classes.

Interorganizational business processes aim to integrate local processes to support the seamless cooperation of organizations. Process view approaches are an adequate method balancing the communication requirements for enabling collaboration and the required privacy hiding internals of private business processes. We focus on a top-down scenario for the development of interorganizational processes, where first an abstract global process is designed. Then each step of the global process is assigned to one of the partners and a local process is generated for each partner as a view on the global process. Finally, the partners implement or adopt their processes based on their views. We present an algorithm for the fully automatic generation of views for any block-structured input process with arbitrary partner assignments, provide a method for merging the partner's views to reconstruct the global process and prove the correctness of the view generation method.

This paper deals with the challenge to create an authorization and authentication infrastructure for virtual knowledge spaces. Virtual knowledge spaces are a concept to build up flexible and adjustable environments for cooperative work and learning processes. When developing authorization concepts f

The comprehensive treatment of time and time constraints is crucial in designing and managing business processes. Process managers need tools that help them predict execution durations, anticipate time problems, pro-actively avoid time constraint violations, and make decisions about the relative process priorities and timing constraints when significant or unexpected delays occur. Variations of activity durations and branching decisions at run-time make it necessary that we treat time management in workflows in a probabilistic way. Therefore we introduce the notion of probabilistic time management and discuss the application of this new concept for workflow design as well as time aware, predictive and proactive workflow execution management.

Probabilistic duration representations can be used to forecast the response time of (composite) Web services, based on empirical data of past executions or calculated from control flow structures. The capability to choose the fastest among similar services or to optimize services based on probable process execution times are only two possible application areas.

The shift from version 9 to version 10 of the "International Statistical Classification of Diseases and Related Health Problems", or ICD (International Classification of Diseases) for short, causes enormous problems for the exploitation of medical data warehouses, since conventional data warehouses do not support the change of the structure of dimensions, i.e. the content and relationships of master data like the diagnostic codes, or other key values. This shortcoming results in a reduction of possible analysis, and unfortunately is the cause of many wrong statistics and analysis results. In this paper, we analyze the problem and show how to superimpose conventional multi-dimensional data warehouses with temporal master data to allow queries spanning multiple periods to return correct answers.

In this paper we present some of the results achieved while realising an international research project aiming at the design and development of an Object-Relational Data Warehousing System ORDAWA. Important goals of the project are to develop techniques for the integration and consolidation of different external data sources in an object-relational data warehouse, the construction and maintenance of materialised relational as well as object-oriented views, index structures, query transformations and optimisations, and techniques of data mining. The achievements discussed in this paper concern the application of materialised object-oriented views in the process of building an object-relational data warehouse.

View integration is an effective technique for developing large conceptual database models. The universe of discourse is described from the viewpoint of different user groups or parts of the system resulting in a set of external models. In a second step these models have to be integrated into a common conceptual database schema. In this work we present a new methodology for integrating views based upon an object oriented data model, where we concentrate on the integration of the behaviour of objects, which is not supported by existing view integration methods.

Workflow management systems (WFMSs) are becoming 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. The authors claim that this can only be achieved by integrating transactional features-especially "workflow transactions"-into WFMSs. Based on this idea, they 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, they distinguish between different workflow types and present adequate recovery concepts for each of them.

Many recursive query processing applications are still poorly supported, partly because implementations of general recursive capabilities are inefficient and hard to understand for users, partly because the approaches do not integrate well with existing query languages. An extension is proposed of the database language SQL for the processing of recursive structures. The new constructs are integrated in the view definition mechanism of SQL. Therefore, users with knowledge of SQL can take advantage of the increased functionally without learning a new language. The construct is based on a generalization of transitive closure and is formally defined. Because of the importance of extreme value sections, special constructs are introduced for the selection of tuples with minimal or maximal values in some attributes. Applying these selections on recursively defined views constitutes nonlinear recursion. By the introduction of special constructs for these selections, dealing with general nonlinear recursion can be avoided.>