CPN Tools 4 : a process modeling tool combining declarative and imperative paradigms

CPN Tools is a tool for modeling, simulating, and analyzing colored Petri nets. The latest iteration of the tool, CPN Tools 4, extends this with constraints known from declarative languages such as Declare and DCR Graphs. Furthermore, this version introduces an explicit process perspective, powerful extensibility allowing third parties to extend the tools capabilities, and a visualization perspective making it possible to make high-level visualizations of executions directly in the tool. In our demonstration, we show how it is possible to create models incorporating declarative and imperative constructs and how to use these models to generate simulation logs that can be directly imported into ProM. We show o¿ the new process perspective on top of colored Petri nets, exemplify the use of the perspective to generate readable Java code directly from models, and show how the visualization perspective makes it possible to show the formal underlying model alongside an easier-to-grasp for non-experts high-level visualization. Our intended audience comprise current users of CPN Tools interested in recent developments and practitioners interested in colored Petri nets and hybrid models. We expect to tailor each demonstration to the wishes of the audience

Flexible Process Notations for Cross-organizational Case Management Systems

In recent times western economies have become increasingly focussed on knowl-edge work. Knowledge work processes depend heavily on the expert knowledge of workers and therefore tend to require more flexibility then the processes seen in traditional production work. Over-constrained processes cause frustration and inefficiency because they do not allow workers to use their expert experience to make the best judgements on how to solve the unique challenges they are faced with. However some structuring of their work is still required to en-sure that laws and business rules are being followed. IT Systems for process control have a large role to play in structuring and organizing such processes, however most of these systems have been developed with a focus on produc-tion work and fail to support the more flexible processes required by knowledge workers. The problem arises at the core of these systems: the notations in which the processes are defined. Traditional process notations are flow-based: control of the process flows from one activity to the next. This paradigm in

Web-Based Modelling and Collaborative Simulation of Declarative Processes.

Abstract. As a provider of Electronic Case Management solutions to knowledge-intensive businesses and organizations, the Danish company Exformatics has in recent years identified a need for flexible process support in the tools that we pro-vide to our customers. We have addressed this need by adapting DCR Graphs, a formal declarative workflow notation developed at the IT University of Copen-hagen. Through close collaboration with academia we first integrated execution support for the notation into our existing tools, by leveraging a cloud-based pro-cess engine implementing the DCR formalism. Over the last two years we have taken this adoption of DCR Graphs to the next level and decided to treat the nota-tion as a product of its own by developing a stand-alone web-based collaborative portal for the modelling and simulation of declarative workflows. The purpose of the portal is to facilitate end-user discussions on how knowledge workers really work, by enabling collaborative simulation of processes. In earlier work we re-ported on the integration of DCR Graphs as a workflow execution formalism in the existing Exformatics ECM products. In this paper we report on the advances we have made over the last two years, we describe the new declarative process modelling portal, discuss its features, describe the process of its development, re-port on the findings of an initial evaluation of the usability of the tool, resulting from a tutorial on declarative modelling with DCR Graphs that we organized at last years BPM conference and present our plans for the future

Safety, Liveness and Run-time Refinement for Modular Process-Aware Information Systems with Dynamic Sub Processes

We study modularity, run-time adaptation and refinement under safety and liveness constraints in event-based process models with dynamic sub-process instantiation. The study is part of a larger pro-gramme to provide semantically well-founded technologies for modelling, implementation and verification of flexible, run-time adaptable process-aware information systems, moved into practice via the Dynamic Condi-tion Response (DCR) Graphs notation co-developed with our industrial partner. Our key contributions are: (1) A formal theory of dynamic sub-process instantiation for declarative, event-based processes under safety and liveness constraints, given as the DCR * process language, equipped with a compositional operational semantics and conservatively extending the DCR Graphs notation; (2) an expressiveness analysis revealing that the DCR * process language is Turing-complete, while the fragment cor-responding to DCR Graphs (without dynamic sub-process instantiation) characterises exactly the languages that are the union of a regular and an omega-regular language; (3) a formalisation of run-time refinement and adaptation by composition for DCR * processes and a proof that such re-finement is undecidable in general; and finally (4) a decidable and practi-cally useful sub-class of run-time refinements. Our results are illustrated by a running example inspired by a recent Electronic Case Management solution based on DCR Graphs and delivered by our industrial partner. An online prototype implementation of the DCR * language (including examples from the paper) and its visualisation as DCR Graphs can be found a