Distributed Enforcement of Service Choreographies

Modern service-oriented systems are often built by reusing, and composing together, existing services distributed over the Internet. Service choreography is a possible form of service composition whose goal is to specify the interactions among participant services from a global perspective. In this paper, we formalize a method for the distributed and automated enforcement of service choreographies, and prove its correctness with respect to the realization of the specified choreography. The formalized method is implemented as part of a model-based tool chain released to support the development of choreography-based systems within the EU CHOReOS project. We illustrate our method at work on a distributed social proximity network scenario.Comment: In Proceedings FOCLASA 2014, arXiv:1502.0315

Data-Aware Interaction in Distributed and Collaborative Workflows: Modeling, Semantics, Correctness

IT support for distributed and collaborative workflows and related interactions between business partners is becoming increasingly important. For modeling such partner interactions as flow of message exchanges, different top-down approaches, covered under the term interaction modeling, are provided. Like for workflow models, correctness constitutes a fundamental challenge for interaction models as well; e.g., to ensure the boundedness and absence of deadlocks and lifelocks. Due to their distributed execution, in addition, interaction models should be message-deterministic and realizable, i.e., the same conversation (i.e. sequence of messages) should always lead to the same result, and it should be ensured that partners always have enough information about the messages they must or may send in a given context. So far, most existing approaches have addressed correctness of interaction models without explicitly considering the data exchanged through messages and used for routing decisions. However, data support is crucial for collaborative workflows and interaction models respectively. This paper therefore enriches interaction models with the data perspective. In particular, it defines the behavior of data-aware interaction models based on Data-Aware Interaction Nets, which use elements of both Interaction Petri Nets and Workflow Nets with Data. Finally, formal correctness criteria for Data-Aware Interaction Nets are derived, guaranteeing the boundedness and absence of deadlocks and lifelocks, and ensuring message-determinism as well as realizability

The play's the thing

For very understandable reasons phenomenological approaches predominate in the field of sensory urbanism. This paper does not seek to add to that particular discourse. Rather it takes Rorty’s postmodernized Pragmatism as its starting point and develops a position on the role of multi-modal design representation in the design process as a means of admitting many voices and managing multidisciplinary collaboration. This paper will interrogate some of the concepts underpinning the Sensory Urbanism project to help define the scope of interest in multi-modal representations. It will then explore a range of techniques and approaches developed by artists and designers during the past fifty years or so and comment on how they might inform the question of multi-modal representation. In conclusion I will argue that we should develop a heterogeneous tool kit that adopts, adapts and re-invents existing methods because this will better serve our purposes during the exploratory phase(s) of any design project that deals with complexity

The play's the thing

For very understandable reasons phenomenological approaches predominate in the field of sensory urbanism. This paper does not seek to add to that particular discourse. Rather it takes Rorty’s postmodernized Pragmatism as its starting point and develops a position on the role of multi-modal design representation in the design process as a means of admitting many voices and managing multidisciplinary collaboration. This paper will interrogate some of the concepts underpinning the Sensory Urbanism project to help define the scope of interest in multi-modal representations. It will then explore a range of techniques and approaches developed by artists and designers during the past fifty years or so and comment on how they might inform the question of multi-modal representation. In conclusion I will argue that we should develop a heterogeneous tool kit that adopts, adapts and re-invents existing methods because this will better serve our purposes during the exploratory phase(s) of any design project that deals with complexity

A Formal Framework for Data-Aware Process Interaction Models

IT support for distributed and collaborative workflows as well as related interactions between business partners are becoming increasingly important. For modeling such partner interactions as flow of message exchanges, different topdown approaches, covered under the term interaction modeling, are provided. Like for workflow models, correctness constitutes a fundamental challenge for interaction models; e.g., to ensure the boundedness and absence of deadlocks and lifelocks. Due to their distributed execution, in addition, interaction models should be message-deterministic and realizable, i.e., the same conversation (i.e. sequence of messages) should always lead to the same result, and it should be ensured that partners always have enough information about the messages they must or may send in a given context. So far, most existing approaches have addressed correctness of interaction models without explicitly considering the data exchanged through messages and used for routing decisions. However, data support is crucial for collaborative workflows and interaction models respectively. This technical report enriches interaction models with the data perspective. In particular, it defines the behavior of data-aware interaction models based on Data- Aware Interaction Nets, which use elements of both Interaction Petri Nets and Workflow Nets with Data. Finally, formal correctness criteria for Data-Aware Interaction Nets are derived, guaranteeing the boundedness and absence of deadlocks and lifelocks, and ensuring message-determinism as well as realizability

Change and Compliance in Collaborative Processes

During their lifecycle, business processes are keen to change. Changes either concern the process model structure or the accompanying rules; e.g. compliance rules (laws and regulations). In the context of business process collaborations, several process partners collaborate together, and changing one process might result in knock-on effects on the other processes; i.e., change propagation. Since business processes are often subject to restrictions that stem from laws, regulations or guidelines; i.e., compliance rules, changing them might lead to the violations of these rules (non-compliability). So far, only the impacts of process changes in choreographies have been studied. In this work, we propose an approach that analyzes and evaluates the impacts of process changes on the different compliance rules and inversely, the impacts of compliance rule changes on the process choreography

Ensuring Compliance of Distributed and Collaborative Workflows

Automated workflows must comply with domain-specific regulations, standards and rules. So far, compliance issues have been mainly addressed in the context of intra-organizational workflows. In turn, there exists only little work dealing with compliance of distributed and collaborative workflows. As opposed to intra-organizational workflows, for distributed and collaborative workflows compliance must be addressed at different levels. This includes local compliance rules of a particular partner as well as global compliance rules to be obeyed by multiple partners collaborating in the distributed workflow. As a particular challenge, the private elements of a particular partner workflow are hidden to the partners and hence not known by them. Accordingly, only limited information is available when checking compliance of distributed and collaborative workflows. This paper introduces techniques enabling compliance checking for distributed and collaborative workflows, taking these privacy constraints into account. Hence it enables ensuring compliance of distributed and collaborative workflows at design time