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      <title-group>
        <article-title>Process and Deviation Exploration with Inductive visual Miner</article-title>
      </title-group>
      <contrib-group>
        <aff id="aff0">
          <label>0</label>
          <institution>Eindhoven University of Technology</institution>
          ,
          <country country="NL">the Netherlands</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Process mining aims to extract information from recorded process data, which can be used to gain insights into the process. This requires applying a discovery algorithm and settings its parameters, after which the discovered process model should be evaluated. Both steps may need to be repeated several times until a satisfying model is found; we refer to this as process exploration. Existing commercial tools usually do not provide models having executable semantics, thereby disallowing for accurate map evaluation, while most academic tools lack features and by the repetitive nature of process exploration, their use is tedious. In this paper, we describe a novel process exploration tool: the Inductive visual Miner. It aims to bridge this gap between commercial and academic tools, by combining the executable semantics of academic tools with the exploration support of commercial tools. It also adds animation and deviation visualisation capabilities.</p>
      </abstract>
      <kwd-group>
        <kwd>Process mining</kwd>
        <kwd>process exploration</kwd>
        <kwd>deviation analysis</kwd>
      </kwd-group>
    </article-meta>
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      <title>-</title>
      <p>
        To gain insights in business processes based on factual knowledge, recorded event
data can be analysed using process mining. Process mining aims to extract
information from recorded process data, stored in an event log, and starts with
discovering a process model from the event log. However, many process
discovery algorithms exist, their parameters have to be set, and the question at hand
might require to focus on speci c parts of the event log. The implications of these
choices are, although well-studied for academic approaches, unclear for the
average user, which makes it di cult to obtain a model that is suitable to answer
the question at hand. In this paper we focus on process exploration, which is the
process of repeatedly trying settings until a satisfactory model is discovered [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>The rst step to take in process exploration is to select a process discovery
algorithm and to set its parameters. Moreover, the scope of the exploration needs
to be set by applying all kinds of lters and choosing a perspective, e.g. one can
focus on the control ow or resource perspective.</p>
      <p>Copyright c 2014 for this paper by its authors. Copying permitted for private and academic
purposes.</p>
      <p>In the second step of the exploration
cycle, one needs to apply the algorithm in
the selected scope to the event log to ob- set scope
tain a process model. Before conclusions use
can be drawn and insights can be gained, process map evaluate prodcisecsosvmerap
the model should be evaluated. For in- process map
stance, compliance related questions, such Figure 1: Exploration cycle.
as whether the four-eyes principle was
adhered to, can only be answered if the model represents a large part of the
behaviour in the event log, and future related questions should only be answered
using models that are likely able to represent future behaviour. Evaluation of a
model with respect to an event log can only be done accurately if the behaviour
that the model allows is well-de ned, i.e. if it has executable semantics, and
di erent parts of the model might have di erent problems.</p>
      <p>Often, general questions, such as what a process looks like, lead to more
speci c questions such as where in the process delays or deviations occur, or to
questions that need to be answered using other perspectives on the event log. Or,
the evaluation shows that the question cannot be answered with the discovered
process model. Then, the parameters need to be set again and a new model must
be discovered; process exploration is a highly iterative process.</p>
      <p>
        After a user has found a suitable model, that model can be used in for instance
automatic enactment of models in systems [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], in automatic prediction [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] and in
compliance checking [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. The full process exploration cycle is shown in Figure 1.
All of these uses for process models require that the model can be processed
automatically, for which it needs to have executable semantics.
      </p>
      <p>Current commercially available process exploration tools o er plenty of
options to set the scope of the exploration, but usually do not produce models
having executable semantics, which thus cannot be used for automated
evaluation or further use. There is plethora of academic tools available to set the scope
of the exploration, to discover a process model and to evaluate it, but given the
nature of process exploration, using them iteratively is tedious. In this paper,
we introduce a tool, Inductive visual Miner (IvM), that aims to bridge this gap
between commercial and academic tools. It supports the steps of process
exploration by chaining existing academic tools and streamlining their use. Moreover,
it improves on evaluation by a new notation and the addition of animation and
quick node selection ltering. Thus far, such capabilities only existed for tools
having no or just weak semantics or without formal guarantees (Fuzzy Miner,
Disco, BPMjOne, Celonis, Perceptive, etc.).</p>
      <p>IvM has been implemented as a plug-in of the ProM framework, which
can be obtained by installing ProM 6.4 from http://promtools.org and,
using the ProM package manager, installing the plug-in Inductive visual Miner.
Example event logs can be obtained from http://www.processmining.org/
logs/start; a screencast is available at http://vimeo.com/user29103154/
inductivevisualminer.</p>
      <p>
        In the remainder of this paper, we explain the implementation of IvM,
highlight the deviation visualisation and give an example. For a detailed comparison
with existing exploration approaches, please refer to [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
2
      </p>
      <p>Inductive visual Miner: Implementation
The architecture of IvM resembles a chain of analysis and visualisation tasks,
shown in Figure 2. To encourage exploration, a user can change any parameter
at any time. IvM will ensure that the current computation is discarded and the
chain is restarted from the rst task that is in uenced by the parameter change.
For instance, if the user selects or deselects a node, only the tasks ` lter node
selection' and `animate' are redone. As especially the align task can take some
time, intermediate visual results are shown to the user until the next task is
nished.</p>
      <p>model
enriched model highlighted model animated model
prepare
log</p>
      <p>lter
activities
discover
align
perspective
activity threshold noise threshold
lter
node selection
selected nodes
animate</p>
      <p>
        In the prepare log task, the events in the log are classi ed using the provided
perspective classi er. Next, in the lter activities task, given a threshold value,
the most-frequent activities are kept, the events of other activities are ltered
out. The Inductive Miner - infrequent (IMi) [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] discovery algorithm is applied
in the discover task. IMi takes as an input parameter the amount of noise
ltering to be applied to paths and produces a process tree. In the align task, the
traces of the event log are aligned to nd the best matching runs through the
model (needed in case of deviations between model and log) [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. This provides
the information needed to enrich the model with information how often model
elements were executed in the event log. The lter node selection task lters the
aligned traces to keep only those that go through a selected node. The nal task,
animate, computes when traces passed model elements; this information is used
to show a quick animated preview of traces in the log onto the model1. If the
log contains no timestamps, random timestamps are inserted for demonstration
purposes.
      </p>
      <p>
        Once the model is available, it can be exported to ProM for further analysis,
both as a Petri net and as a process tree; a user can perform its own evaluation
without waiting for the evaluation of IvM to nish. At any point during the
exploration, the model can be saved as bitmap (png) and vector (pdf, svg) image
formats. The full animation of the complete log can be exported to bitmap (avi)
and vector (svg) based movie formats once it is computed.
1 At time of writing, we limited the quick preview to 50 traces for performance reasons.
Deviations. Deviations are a crucial part
of the evaluation: they show precisely C
what parts of the model deviate with 7 1
respect to the log. Deviations are
visualised to show shich parts of the model t 1
well and which parts do not. This is
important for drawing reliable conclusions. Figure 3: Model with the result of
Two types of deviations have been identi- the align task. The edge
circumvented [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]: if a trace contains an event that is ing C denotes a model move; the
not allowed by the model, it is a log move; self-edge on the right a log move.
if the model requires an event that is not
present in the trace, it is a model move. Log and model moves are identi ed
by the align task, that chooses a run through the process model such that the
number of such deviating moves is minimal. As shown in Figure 3, IvM visualises
both of them using dashed red edges; such an edge that circumvents an activity
represents a model move, while a self-edge represents a log move.
Example. Figure 4 shows the initial model with default values for all parameters.
Looking at this model, the question rose what the happy ow of the process
was, i.e. the most frequently taken path. After a few iterations, parameters were
settled: using only the 50% most frequent activities and applying noise ltering
of 20%, a happy ow of 6 activities was uncovered. Before exporting this model
for further analysis, the deviation visualisation was turned on, resulting in the
model shown in Figure 4b. This shows that the fourth and fth activity are often
skipped.
      </p>
      <p>(a) Default parameters.</p>
      <p>(b) After a few iterations; with deviations and animation.
In this paper, we discussed the cycle of process exploration, consisting of
repeatedly setting parameters, discovering a process model and evaluating it. We
identi ed a gap between existing commercial and academic process exploration
tools: commercial tools usually do not provide models having executable
semantics, thereby disallowing for accurate map evaluation, while most academic tools
lack features such as seamless zooming and animation, thus do not support the
repetitive nature of process exploration well.</p>
      <p>We introduced a process exploration tool, Inductive visual Miner (IvM), that
aims to bridge this gap. When started, IvM immediately applies a chain of
analysis and visualisation tasks to show the user not only a model, but also the
traces of the event log animated on it, and where the log and model deviate from
one another. IvM encourages the user to interact by enabling setting parameters
at anytime: computations will be restarted as necessary in the background. IvM
is not as feature-rich as some of the commercial tools, but shows that it is
possible to use powerful techniques with formal guarantees in a user-friendly
package. We hope that IvM will inspire commercial vendors to consider models
with executable semantics and support deviation analysis. Extensions to IvM
can be made in all tasks, for instance other process tree discovery algorithms
can be plugged in instead of IMi.</p>
      <p>In the future, we'd like to include approximation algorithms to compute the
alignments in order to speed it up. To allow for even better evaluation, several
extensions are possible, such as global quality measures ( tness, precision and
generalisation) and identi cation of traces in the animation. Furthermore, several
other lters such as lters on speci c activity, timestamp, resource and on data
could be included to give a user more freedom in setting the scope.</p>
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