=Paper=
{{Paper
|id=Vol-1295/paper3
|storemode=property
|title=WoPeD - An Educational Tool for Workflow Nets
|pdfUrl=https://ceur-ws.org/Vol-1295/paper3.pdf
|volume=Vol-1295
|dblpUrl=https://dblp.org/rec/conf/bpm/FreytagS14
}}
==WoPeD - An Educational Tool for Workflow Nets==
https://ceur-ws.org/Vol-1295/paper3.pdf
WoPeD - An Educational Tool for Workflow Nets
Thomas Freytag, Cooperative State University (DHBW) Karlsruhe, Germany
freytag@dhbw-karlsruhe.de
Martin Sänger, 1&1 Internet AG, Karlsruhe, Germany
m.saenger09@web.de
Abstract
WoPeD stands for Workflow Petrinet Designer and is an open-source
software distributed over the Sourceforge1 platform. WoPeD’s focus lies
on verification, visualization and explanation. Over the years, WoPeD has
become a widely-used tool in the academic sector. This demo will provide
information about recently added and improved features and functions.
The demo will show how to use WoPeD as an e-learning tool to get a
better understanding of fundamental BPM concepts2 .
Keywords: Workflow nets, simulation, explanation, visualization, e-
learning, open-source.
1 About WoPeD
The development of WoPeD started in 2003. Since then, the software has been
extended continuously, leading to the current version 3.2.0 released in June
2014. WoPeD has been downloaded more than 45,000 times since the initial
release and has been successfully utilized in lectures, projects, case studies and
scientific publications in many universities worldwide. WoPeD covers a variety
of BPM aspects. Firstly, it provides a graphical editor for standard Petri nets
and workflow nets including an interactive simulator. Secondly, it supports
model verification and property visualization, e. g. has built-in algorithms for
soundness, process metrics, and quantative simulation. Thirdly, it allows the
transformation from and to other common model formats like BPMN. Overall,
WoPeD has proved to be a handy and easy-to-use e-learning tool mainly for
the academic sector allowing students and practioners easy access, hands-on
experience and fast aquisition of the major concepts of business process modeling
and verification.
2 Functional Features of WoPeD
Process and Resource Editor
In the WoPeD editor, the user can to draw, annotate, manage and export reg-
ular place-transition Petri nets as well as workflow (WF) nets according to the
van der Aalst notation as introduced in [1]. The editor supports hierarchical
sub-processes as transition refinements, enablingWoPeD to handle also large
1 www.sourceforge.org
2 Copyright © 2014 for this paper by its authors. Copying permitted for private and
academic purposes.
process models. A layout beautifier is provided to re-arrange the process graph
in a human-readable representation. Moreover, WoPeD contains a graphical re-
source model editor covering the organization view of BPM, by defining resource
objects, roles, and groups.
PNML Compliance and Import/Export Formats
The underlying file format complies to standard PNML, allowing models created
by WoPeD to be exchanged with other PNML-aware tools. WoPeD saves its
“proprietary” data into a separate part of the PNML stream such that third-
party tools can access the basic control structure and skip all WoPeD-internal
extensions. Additionally, WoPeD can export to graphical formats (PNG, JPEG)
and (experimentally) to BPEL[4].
Figure 1: Soundness wizard
Soundness Checker
WoPeD contains an implementation of the soundness algorithm, including con-
tributing structural and behavioural properties like free-choice, S-coverability,
and PT/TP handles. The user can choose to run these checks in wizard mode,
where a visual explanation engine guides him through all verification steps in-
tuitively, or alternatively in expert mode showing a compact. tree-like property
structure. Figure 1 shows a WF net process model and an analysis session in
wizard mode. In both modes, a high focus is laid to visualizing a soundness
failure by interactively referring to the associated editor elements.
Interactive Simulator and Coverability Graph Visualization
WoPeD provides a highly intuitive token game simulator allowing to navigate
through Petri net executions stepwise or automatically. For sub-processes, there
exists a step-into/step-over logic similar to an interactive source code debugger.
WoPeD contains algorithms to construct the coverability graph of a Petri net,
allowing various behaviour-related property checks. Additionally, the coverabil-
ity graph can be displayed, showing the behaviour of the associated Petri net
and allowing manual inspection and navigation, e. g. to study and understand
the concepts of occurrence rule, marking and reachability visually.
Figure 2: Capacity planning results
Quantitative Simulation and Capacity Planning
WoPeD supports also quantitative simulations. A built-in resource editor allows
for each process the definition of a resource model, i. e. roles, groups, and
objects. Additionally, transitions can then have resource class assignments.
Two different algorithms are implemented, follwing the suggustions of [1], both
based on stochastic distributions of arrival rate, task service times and XOR
branching probabilities: Firstly, a quantitative simulator engine for the random
construction of execution traces, allowing to derive quantitative properties like
average waiting or completion time. Secondly, a capacity planner in order to
calculate the optimal number of resource objects for each resource class. Figure
2 shows a capacity planning result based on quantitative parametrization of a
process model.
Figure 3: Operator coloring and process metrics
Research Support Tool
WoPeD has been used as a proof-of-concept tool for several research ideas in the
BPM community. Firstly, WoPeD can detect so called matching operator pairs,
using a coloring scheme to visualize corresponding split and join transitions in
the style of syntax highlighting in programming editors. A summary of these
research results can be found in [6], the implementation aspects were discussed
in [4]. Secondly, a component was developed within WoPeD to edit and visualize
process metrics and their relation to the process graph [5]. The algorithms make
use of a built-in variant of BPStruct [3, 7]. Figure 3 shows WoPeD with enabled
operator coloring and a list of process metric values and their visual classification
on the sidebar.
Figure 4: AProMoRe configuration panel and import dialog
AProMoRe Repository Front-End
AProMoRe is another open source software developed at QUT Brisbane [2]. It
provides roughly a set of conversion algorithms between most common process
model formats, e. g. BPMN, EPML or YAWL. The most recent feature of
WoPeD is an interface to access documents stored in an AProMoRe repository.
It is possible to import any type of process model from AProMoRe (no matter
what its native format is) into WoPeD and also to export a PNML process
from WoPeD to AProMoRe. This allows to make use of WoPeDs analysis or
visualization functionality also to process models not created with WoPeD and
even in different process model formats. Figure 4 shows the configuration panel
and the import dialog to load a process model into WoPeD.
3 Availability of WoPeD
WoPeD can be downloaded on its homepage [8]or directly from Sourceforge.
The code is open source and is published under the LGPL license. WoPeD is
written in Java. For convenience, there exist three different installer packages
for the major platforms Windows, Linux and Mac OS.
References
[1] W. M. P. van der Aalst, K M. van Hee: Workflow Management: Models,
Methods, and Systems MIT Press 2002.
[2] AProMoRe website: www.apromore.org, accessed in May 2014.
[3] BPStruct. www.sep.cs.ut.ee/Main/bpstruct, accessed in May 2014.
[4] A. Eckleder, T. Freytag, J. Mendling, H.A. Reijers: Realtime Detection and
Coloring of Matching Operator Nodes in Workflow Nets. In T. Freytag and
A. Eckleder (ed.), 16th German Workshop on Algorithms and Tools for Petri
Nets, volume 501 of CEUR Workshop Proceedings, pages 56-61, 2009.
[4] A. Eckleder and T. Freytag: WoPeD 2.0 goes BPEL 2.0. AWPN 2008 -
Research Report, University of Rostock, 2008.
[5] J. Mendling: Metrics for Process Models, Springer Verlag, Berlin, 2008.
[6] H. A. Reijers, T. Freytag, J. Mendling, A. Eckleder: Syntax highlighting in
business process models. Decision Support Systems 51(3): 339-349 (2011).
[7] M. Weidlich, A. Polyvyanyy, J. Mendling, and M. Weske. Petri Nets, volume
6128 of Lecture Notes in Computer Science, pages 63– 83. Springer, 2010.
In: LNCS 6128, Petri nets, pages 63– 83. Springer, 2010.
[8] WoPeD website: www.woped.org, accessed in May 2014.