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  <front>
    <journal-meta>
      <issn pub-type="ppub">1613-0073</issn>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Visualizations in Conformance Checking</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Nikolaos Theofanopoulos</string-name>
          <email>nikolaos.theofanopoulos@students.uni-mannheim.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Michael Grohs</string-name>
          <email>michael.grohs@uni-mannheim.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Download/Demo URL</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Documentation URL</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="editor">
          <string-name>Process Mining, Conformance Checking, Visualization</string-name>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Microsoft Windows</institution>
          ,
          <addr-line>MacOS</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>React.tsx</institution>
          ,
          <addr-line>Python, PM4Py</addr-line>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>University of Mannheim</institution>
          ,
          <addr-line>L15 1-6, 68161 Mannheim</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2025</year>
      </pub-date>
      <fpage>20</fpage>
      <lpage>24</lpage>
      <abstract>
        <p>Conformance checking, a core activity in process mining, compares real-world process executions recorded in event logs to intended process behavior captured in process models. While numerous conformance checking techniques exist, their practical adoption remains limited. One contributing factor to this is that visualizations might not be suited to address the underlying user purposes. In that light, recent work has introduced a taxonomy of conformance checking tasks that captures purposes when applying conformance checking. However, current tools neither systematically evaluate their visualizations against this taxonomy nor provide integrated support for end-to-end conformance analysis. To address this gap, this paper presents CC Viz, a tool that ofers five targeted visualizations, each tailored to a specific task from the taxonomy. The tasks-ranging from exploring guideline violations to presenting the impact of conformance on process outcomes-are organized as a sequential analysis pipeline. CC Viz enables users to switch between visualizations and interactively drill down into specific conformance violations, facilitating a holistic and task-aligned conformance analysis experience.</p>
      </abstract>
      <kwd-group>
        <kwd>Metadata description</kwd>
        <kwd>Legal code license</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>CEUR</p>
      <p>ceur-ws.org
Source code repository
Screencast video</p>
    </sec>
    <sec id="sec-2">
      <title>1. Introduction</title>
      <p>Value
CC Viz
1.0
Apache 2.0
https://github.com/michaelgrohs/ccviz/blob/master/README.md
https://github.com/michaelgrohs/ccviz
https://github.com/michaelgrohs/ccviz/blob/master/demonstration.mov
developed. They are able to detect conformance violations whenever a trace diverges from the
process model [2]. All techniques require a process model and an event log as input [1]. Based
on that, users can automatically derive non-conform behavior and also directly assess which
parts of traces were not desired [3].</p>
      <p>Regardless of these capabilities, conformance checking is rarely applied in practice [4, p. 39].
This can be attributed to multiple reasons. For example, many conformance checking techniques
require significant computational resources, leading to long waiting times during their usage [ 5].
Another reason is the reliance on process models, which may not be available in organizations
since it is time-consuming and error-prone to create and maintain them [2].</p>
      <p>In this demo, we address another reason for the lack of conformance checking usage in
practice: the suitability of visualizations to address users’ needs when applying conformance
checking. These needs are the purpose that a user has when using conformance checking, or,
in other words, the task the user wants to fulfill [ 5]. Recently, a taxonomy of conformance
checking tasks has been proposed, summarizing manifold purposes of conformance checking
[5]. The taxonomy consists of six dimensions:
• task goal: why the task is done (e.g., explore, confirm)
• task means: how the task is carried out (e.g., discover, compare)
• data characteristics: what should be revealed (e.g., conformance, guideline violations1)
• constraint type: the perspective referred to (e.g., control-flow, data)
• data target: the data on which the task is carried out (e.g., log, trace)
• data cardinality: the cardinality of the data target (e.g., all, many)
Through this, users are able to communicate what they want to achieve with conformance
checking. However, existing visualizations in commercial or scientific tools are not evaluated
w.r.t. whether they address these tasks. Additionally, existing tools predominantly contain
standalone visualizations, meaning that there is no support for a wholistic conformance analysis.</p>
      <p>
        To address this gap and closely align the visualization of conformance checking results with
the underlying tasks, we present the CC Viz tool. Given a process model and an event log as
input, the tool visualizes conformance checking results that address five common tasks of the
dimensions ‘task goal: task means, data characteristics’:
(
        <xref ref-type="bibr" rid="ref1">1</xref>
        ) Explore: Identify, Guideline violations
(
        <xref ref-type="bibr" rid="ref2">2</xref>
        ) Describe: Identify, Guideline violations
(
        <xref ref-type="bibr" rid="ref3">3</xref>
        ) Describe: Present, Conformance distribution
(
        <xref ref-type="bibr" rid="ref4">4</xref>
        ) Explain: Discover, Reasons for guideline violations
(
        <xref ref-type="bibr" rid="ref5">5</xref>
        ) Present: Compare, Impact of conformance on process outcome
We use these tasks as they can be considered a sequential analysis pipeline for conformance
checking, starting with task (
        <xref ref-type="bibr" rid="ref1">1</xref>
        ) and ending with task (
        <xref ref-type="bibr" rid="ref5">5</xref>
        ) [5]. We abstract from the remaining
dimensions constraint type, data target, and data cardinality as they do not change the purpose
and are typically visualized similarly. Consequently, CC Viz consists of five distinct
visualizations, from which each is suited to one task from taxonomy [5]. The tool allows users to switch
between visualizations and contains interactive features to view problems in greater detail.
      </p>
      <p>In the remainder of this paper, we introduce the CC Viz tool with all its functionalities in
section 2, after which we illustrate its maturity in section 3 and conclude in section 4.
1Note that guideline violations most commonly refer to deviations from a process model [5].</p>
    </sec>
    <sec id="sec-3">
      <title>2. The CC Viz Tool</title>
      <p>At https://github.com/michaelgrohs/ccviz, the CC Viz tool can be accessed. In this repository,
the user can find the source code, instructions on how to run the tool, and further documentation.
A demo video is available at https://github.com/michaelgrohs/ccviz/blob/master/demonstration.
mov. Alternatively, it is also possible to access the tool in a hosted setting without requiring any
local setup via https://ccviz-frontend.vercel.app. This relies on a hosted backend service Render
(https://render.com) and a frontend service Vercel (https://vercel.com). Note that performance
is significantly slower than the local setup and the backend service is sleeping per default. Thus,
the functionalities are not available directly and has to be woken up. Also, the service restricts
RAM to 512 MB, meaning that it cannot handle larger files (the default dataset works).</p>
      <sec id="sec-3-1">
        <title>2.1. Functional Components</title>
        <p>
          As illustrated in Fig. 1, a process model and an event log are required as input for CC Viz. Then,
all relevant computations are performed simultaneously for all tasks once, meaning that no
waiting times are required after that. This computation uses current state-of-the-art
alignmentbased conformance checking as basis which provides detailed feedback on skipped and inserted
activities per trace as well as fitness levels. Following that, the user enters the task-specific
visualizations, starting with task (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ). It is possible to switch between the visualizations, moving
to the next up- or downstream task in the sequence. In the following, we present the five
visualizations in more detail using the travel reimbursement process from the BPI Challenge
2020 (BPIC20) 2 as running example. The corresponding process model is obtained from [6].
Event
Log
Process
Model
        </p>
        <sec id="sec-3-1-1">
          <title>Computation</title>
          <p>
            (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) Explore: Identify,
Guideline violations
          </p>
        </sec>
        <sec id="sec-3-1-2">
          <title>Visualization</title>
          <p>
            (
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) Describe: Identify,
Guideline violations
(
            <xref ref-type="bibr" rid="ref3">3</xref>
            ) Describe: Present,
          </p>
          <p>
            Conformance distribution
(
            <xref ref-type="bibr" rid="ref4">4</xref>
            ) Explain: Discover, Reasons for
guideline violations
(
            <xref ref-type="bibr" rid="ref5">5</xref>
            ) Present: Compare, Impact of
conformance on process outcome
(
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) Explore: Identify, Guideline violations. This first task aims to identify where exactly
traces difer from the desired behavior defined by the model. Corresponding violations are
identified by users in an exploratory manner. To address this task, CC Viz shows the provided
BPMN and color codes the degree of conformance per activity, light colors indicating conform
activities and darker colors indicating violations (Fig. 2). This degree of conformance is defined
by the proportion of traces in which an activity has been skipped or inserted, as detected by the
trace alignments. The number of skips and insertions are also portrayed for activities when
hovering over them. Thus, the user can explore which activities pose problems in the process.
For BPIC20, most of the process is conform but administration approval appears problematic.
(
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) Describe: Identify, Guideline violations. The second task aims to identify what behavior
was executed instead of the behavior captured in the process model. The task is similar to task
(
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) but does not explore the violations and rather directly describes them. For this, CC Viz
contains a bar chart per activity with one bar showing skip frequency and another bar showing
insertion frequency (Fig. 3). In BPIC20, administration approval is often inserted.
(
            <xref ref-type="bibr" rid="ref3">3</xref>
            ) Describe: Present, Conformance distribution. The third task describes which percentage
of traces in the log fall into which conformance category. These categories are defined by trace
iftness values. CC Viz shows the fitness distribution of traces with a bar chart (Fig. 4). Thereby,
traces are sorted into bins with size 0.1. When clicking on a bar, the event sequences within
this bar are shown. In BPIC20, most traces are conform but 134 traces deviate significantly.
(
            <xref ref-type="bibr" rid="ref4">4</xref>
            ) Explain: Discover, Reasons for guideline violations. The fourth task aims to explain
which attributes are responsible for guideline violations. To address this task, CC Viz contains a
chart that shows the fitness grouped by all trace and event attributes in the log (Fig. 5). Attributes
are selected by the user. For categorical attributes, a bar chart is presented. For numerical
attributes, a scatterplot is displayed. This allows to deduce which values might cause guideline
violations. For instance, the role MISSING correlates significantly with low fitness in BPIC20.
(
            <xref ref-type="bibr" rid="ref5">5</xref>
            ) Present: Compare, Impact of conformance on process outcome. The last task aims to
compare the impact of conformance on the process outcome. The process outcome is thereby
defined as a binary feature, either positive (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) or negative (0). The definition of the process
outcome is done by the user. Concretely, it can be defined based on the trace containing or
ending with a certain key activity. Per default, it is defined as a correct execution of the last
activity. For example, for BPIC20, a trace is considered to have a positive outcome if it ends
with Payment Handled. CC Viz displays a bubble chart with the percentage of traces with a
positive outcome per bin of trace-level fitness (Fig. 6). Thus, users can see if traces with lower
iftness also tend to have fewer positive outcomes, which is the case for BPIC20.
          </p>
        </sec>
      </sec>
      <sec id="sec-3-2">
        <title>2.2. Tool Architecture</title>
        <p>In CC Viz, a Python-based back-end and a React-based front-end communicate through request
and response mechanisms. The back-end utilizes Flask to ensure communication even if the
front-end is closed. Further, PM4Py’s trace alignments [7] handle the conformance check.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>3. Maturity</title>
      <p>We used the tool for the processes of the BPI Challenges 2012 (sub-process with A_ and O_
activities only; 12A &amp; 12O) and 2020 (Domestic Declarations (Dom.), International Declarations
(Int.), Request for Payment (RfP), and Prepaid Travel Costs (Prep.)) obtained from [6] as well
as the sepsis process [8] and the road trafic fines process obtained from [ 5]. These processes
represent a variety of examples with respect to size, complexity, and count of recorded attributes.</p>
      <p>
        Tab. 1 shows descriptive statistics for all used event log-process model pairs and required
computation times. We see that CC Viz is heavily impacted by the computation of alignments,
which is time-intensive for processes with many, long variants and complex models like Sepsis
with 354 seconds (about 5.8 minutes). Road trafic also takes relatively long due to its size with
122 seconds (about 2.0 minutes). All other processes take less than 30 seconds. This indicates
that the attribute processing for task (
        <xref ref-type="bibr" rid="ref4">4</xref>
        ) does not afect times. In summary, computations require
time, mainly due to trace alignments, but remain below 6 minutes even for complex processes.
# Event # Trace
Attributes Attributes
      </p>
      <p>Computation</p>
      <p>Time</p>
    </sec>
    <sec id="sec-5">
      <title>4. Conclusion</title>
      <p>We presented CC Viz, a tool for the visualization of conformance checking results. It aims to
provide visualizations that are tailored exactly to the purpose that users have when applying
conformance checking. To achieve that, the visualizations are based on tasks identified in a
corresponding taxonomy [5] and accessible in a common sequential analysis pipeline. In the
future, we aim to empirically assess whether users can use CC Viz to solve the underlying tasks.</p>
    </sec>
    <sec id="sec-6">
      <title>Declaration on Generative AI</title>
      <p>The authors used ChatGPT, DeepL for: Grammar &amp; spelling check, Paraphrase &amp; reword. The
authors reviewed and edited the content as needed and take full responsibility for all content.</p>
    </sec>
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