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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Comprehensive Business Process Management through Observation and Navigation</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Stefan Schönig</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Michael Zeising</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Stefan Jablonski</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Applied Computer Science IV, University of Bayreuth</institution>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Most real-world business processes involve a combination of both well-defined and previously modelled as well as unforeseen and therefor unmodelled scenarios. The goal of comprehensive process management should be to cover all actually performed processes by accurate models so that they may be fully supported by IT systems. Unmodelled processes can be observed by the Process Observation system which generates models reflecting the recorded behaviour. Modelled processes may be of different natures: while so-called “automation” processes involve little human participation and mainly orchestrate services and applications, so-called “knowledge-intensive” processes are based on human expert participation. Both types of models may be enacted by the Process Navigation system. This contribution introduces the integration of both systems which leads to an approach for supporting the full range from unmodelled processes to both automation and knowledge-intensive processes as well as the transition from unmodelled to modelled processes.</p>
      </abstract>
      <kwd-group>
        <kwd>Business processes</kwd>
        <kwd>workflow</kwd>
        <kwd>process observation</kwd>
        <kwd>declarative process modelling</kwd>
        <kwd>process mining</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>
        Business process management (BPM) is considered an essential strategy to create and
maintain competitive advantage by modelling, controlling and monitoring production
and development as well as administrative processes [
        <xref ref-type="bibr" rid="ref1 ref2">1, 2</xref>
        ]. Many enterprises and
organizations adopt a process model-based approach to manage their operations.
Ideally, this involves surveying and modelling the as-is processes and designing to-be
processes in a way so that they may be supported by BPM technologies. In reality,
areas remain in which the as-is process may not be documented in a formal way so
that they may not be supported by traditional workflow systems. As a consequence,
these areas are then excluded from IT support. However, it is desirable that these
unmodelled processes are supported by an IT system as well and that, ideally, this
system offers suggestions for modelling these processes. This paper presents an
approach for fluently covering both situations: the execution of modelled business
processes and the support during unmodelled situations with a reconstruction of the
actually performed process. Figure 1 gives an overview over the structure of the approach.
The Process Observation (PO) system covers the support of unmodelled processes.
Based on collected execution information, best practice patterns are provisioned to
users. These patterns are emerging with progressing enactment as the data basis
grows. On the other hand, the Process Navigation (PN) system executes modelled
processes. We differentiate between so-called “knowledge-intensive” and
“automation processes”. In Section 2 we will have a closer look at this differentiation. We will
justify why the application of different modelling concepts, the declarative modelling
approach for knowledge-intensive processes and the imperative modelling approach
for automation processes respectively, is suitable. Both types of process models can
be executed by the PN system. For supporting both modelled and unmodelled
business processes, the two components PN and PO must be integrated. Hence, PO makes
use of collected information and generates executable process models. These models
can finally be enacted by the PN system.
      </p>
      <p>Declarative Process Mining</p>
      <p>Imperative Process Mining
Knowledgeintensive</p>
      <p>Automation
Emerging Patterns</p>
      <p>Declarative Models</p>
      <p>Imperative Models
high flexibility / less support</p>
      <p>high rigidity / high support</p>
      <p>Degree of rigidity / support
Type of Process</p>
      <p>Unmodelled
IT Support based on
IT System</p>
      <p>This paper is structured as follows: Section 2 outlines the basic principles of the
execution component for modelled processes. Section 3 guides through the ideas
behind the observation component for firstly unmodelled processes. Section 4 shows
how the two components are integrated. Section 5 outlines the related work on
flexible process execution and process mining. Finally, section 6 concludes the article,
goes into the current limitations of the approach and provides an outlook on planned
future work.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Navigating through Modelled Business Processes</title>
      <p>
        Generally, IT support for business processes requires a compromise between control
and flexibility [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Current solutions for executing modelled processes primarily focus
on control. They support processes with little human participation, predetermined
paths and predictable choices that focus on orchestrating services and applications [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
We call this type of processes the “automation processes”. They are well understood
and highly evolved solutions exist on the market. “Knowledge-intensive processes”,
on the contrary, are driven by human participation, often contain unforeseen paths and
mostly depend on human decisions. The goal of the PN system is to execute this type
of business processes models.
2.1
      </p>
      <sec id="sec-2-1">
        <title>Declarative Process Modelling</title>
        <p>
          Following the terminology of programming languages, there are two paradigms of
describing business process models: the imperative and the declarative style [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. The
imperative way corresponds to imperative or procedural programming where every
possible path must be foreseen at design time and encoded explicitly. If a path is
missing then it is considered not allowed. Classic approaches like the BPEL [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ] or
BPMN [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ] follow the imperative style and are therefore limited to the structured type
of processes. In declarative modelling, on the other hand, process models specify the
possible ordering of events implicitly by constraints instead of explicitly specifying
all the allowed sequences of tasks. As a result, Process Navigation relies on a
declarative representation for supporting knowledge-intensive business processes.
2.2
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>Cross-Perspective Modelling</title>
        <p>
          Declarative modelling is based on constraints that relate events of the process and
exclude or not recommend certain correlations. Both constraints and events must be
able to involve all the perspectives of a business process like, e.g., incorporated data,
agents performing the work and utilized tools [
          <xref ref-type="bibr" rid="ref7">7</xref>
          ]. On this way it becomes possible to
express realistic correlations like, e.g., the actual performing agent of a step affecting
the type of data used in another step [
          <xref ref-type="bibr" rid="ref8">8</xref>
          ].
2.3
        </p>
      </sec>
      <sec id="sec-2-3">
        <title>Different Modalities and Explanation</title>
        <p>A business process usually consists of several “facets” like, e.g., a legal framework
(mandatory, “must”) and best practice (recommended but facultative, “should”).
Classic approaches like the BPMN only allow for describing one of these facets per
model. Combining both of them in one model greatly enhances its documentary
character and allows for a BPM system to act more flexibly. An action that, e.g., is
contrary to best practice but conforms to the legal framework is offered but marked as not
recommended. The BPM system may even explain why the action is not
recommended by tracing it back to the process model.
2.4</p>
      </sec>
      <sec id="sec-2-4">
        <title>Implementation of the Declarative Execution Core</title>
        <p>
          The PN engine interprets declarative process models and recommends tasks to
participants and manages process data. Therefore, it has to find next feasible actions
based on the process constraints (model) and the already performed actions (log).
Additionally, feasible actions need to be categorised into feasible but not
recommended and recommended actions. This task is represented as a planning problem and
solved by the search-based optimisation framework JBoss Drools Planner. Based on
the current event log, it generates all feasible next actions within the boundaries of the
process’s hard constraints (e.g. legal restrictions) and scores these actions on the basis
of the soft constraints (e.g. best practice). Each time an action violates a soft
constraint this violation is serves for explaining to participants why the action is not
recommended. The details of this implementation can be found in [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ].
2.5
        </p>
      </sec>
      <sec id="sec-2-5">
        <title>Imperative Execution Core and Adaptability</title>
        <p>As mentioned above, knowledge-intensive processes do not replace automation
processes. Situations remain where an imperative style of description is best suited. To
come up with this situation, the PN consists of two distinct execution cores for each
paradigm on a common foundation layer. Both automation and knowledge-intensive
processes may be executed by the same system and many common aspects like
persistence, transaction management and management of process data are shared.
3</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Observing and Analysing Unmodelled Business Processes</title>
      <p>
        Even though Process Navigation provides more flexibility to participants by
supporting knowledge-intensive processes, the execution of business processes is still based
on a predefined process model. In situations where no model can be foreseen the
process must be performed without support. Comprehensive process management
requires methods to overcome the separation of modelling and execution phase by
applying observation and analysis methods of executed processes [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ].
3.1
      </p>
      <sec id="sec-3-1">
        <title>Observing Process Execution</title>
        <p>
          In order to support unmodelled situations, the “actually” performed process needs to
be recorded. Process Observation (PO) [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ] provides a solution where participants
record, i.e., “digitize”, what they are currently doing, i.e., they provide information
about the process they are performing. By providing information about the process
steps as well as incorporated data objects, the system accumulates execution
information that can be used to automatically generate process models and dynamic guidance
feedback for future process execution [
          <xref ref-type="bibr" rid="ref11 ref14">11, 14</xref>
          ]. Additionally, it is desirable that the
observation of unmodelled processes is already supported by an IT system. We
identify two different types of support mechanisms: structural and behavioural support
functionality.
        </p>
        <p>
          Structural Support during Observation. Structural support mechanisms depend
on process “skeletons” which consist solely of process steps. These serve as static
guidelines, i.e., independent of the users’ behaviour. By starting a special process,
these mandatory steps are displayed to the user. This way, participants can leverage
“templates” and additionally complete process information with dynamically
occurring missing steps. Structural support mechanisms are implemented by adopting
concepts of Adaptive Case Management (ACM) systems [
          <xref ref-type="bibr" rid="ref12 ref13">12, 13</xref>
          ].
        </p>
        <p>
          Behavioral Support during Observation. Behavioural support functionality
makes use of the recorded process execution information. PO discovers workflow
patterns that provide guidelines through the process. As the data basis grows with
progressing enactment, quantity and quality of discovered workflow patterns will
dynamically change. We adapted association rule mining to analyse process execution
logs [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ]. The resulting association rules are used for guiding process participants
through process execution. Therefore, the collected process execution information of
the PO is periodically transformed to an input dataset for association rule mining. The
transformation algorithm is described in [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ]. Subsequently, the Apriori algorithm is
applied to this dataset. The algorithm extracts a set of association rules. Rule (1), e.g.,
claims that every time process step B has been performed after step A, process step C
followed (numbers represent time steps).
        </p>
        <p>A(0) ∧ B(1) → C(2)
(1)</p>
        <p>The PO system manages currently extracted association rules. If a users’ behaviour
satisfies the left-hand side of a rule, i.e., in this case a user performed step B after step
A, the right-hand side of the rule is recommended, i.e., to continue by process step C.
3.2</p>
      </sec>
      <sec id="sec-3-2">
        <title>Evolution of Imperative Process Models</title>
        <p>
          Although, the PO system supports users by structural and behavioural guidelines, the
development of complete process models, e.g., for documentation purposes or
workflow management system (WfMS) deployment, remains the main goal. Therefore, the
PO system extracts knowledge from event logs using process mining [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ] techniques.
In cases where the recorded information represents a structured process, where every
possible path can be described clearly, the generation of an imperative process model,
e.g., a BPMN model can be initiated. There are several well-known imperative
process mining techniques that can be used to generate this kind of model [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ]. Since the
PN system provides an engine component for imperative modelling languages like
BPMN [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ], extracted models can deployed and executed by the navigation system.
The PO system allows for the evolution of complete process models that form the
basis for future process execution with the help of a WfMS.
3.3
        </p>
      </sec>
      <sec id="sec-3-3">
        <title>Extraction of Declarative Process Models</title>
        <p>
          Imperative process mining techniques construct models explicitly encoding all
possible behaviours [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ]. In contrast to imperative modelling, declarative models
concentrate on describing what has to be done and the exact step-by-step execution order is
not directly prescribed. There are several process mining approaches that are
discovering declarative constraints. The approach of [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ] is included in the PO system and
enables the extraction of declarative process models that can be executed by the
declarative engine component of the PN system [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ]. As the declarative models always
consider all possible solutions, the number of paths through the model can become
incredibly large [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ]. This is why guidance through a flexible process model is
necessary [
          <xref ref-type="bibr" rid="ref17">17</xref>
          ]. Therefore, best-practice workflow patterns serve as guidelines through the
process. The combination of declarative guardrails and best practice guidelines finally
forms an all-embracing input for powerful execution support through the application
of the PN system.
4
        </p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Integrating Process Observation and Navigation</title>
      <p>For seamlessly supporting both modelled and unmodelled business processes, PN and
PO must be integrated. The first task is to find a common data model for representing
the entities of process models (e.g. processes, resources, data objects) and their logs
(e.g. events, projects, values). Processes may be represented as BPMN or DPML
(declarative process modelling language) process models and may consist of
subprocesses. Further model entities are the resources that perform process steps and data
objects that may be produced or consumed. When a process is executed an instance is
created. Process steps may be activated, i.e., assigned to potential performers and
completed by an actual performer. When a step is completed values of data objects
may be consumed and/or produced. The PN component writes execution logs, i.e.,
events when executing processes and may read reconstructed process models for
executing them. The PO component also writes events when observing unmodelled
processes and writes models after analysing event logs.
4.1</p>
      <sec id="sec-4-1">
        <title>Specialization of Process Steps</title>
        <p>One way of integrating navigation and observation is the refinement of a certain
process step that has been modeled as an atomic step in the first place. The participant
selects the step and chooses to let his/her work to be observed. When the originally
atomic step - which is now a composite process - is finished, PO analyses the
occurred events and generates a process model reflecting the recorded behavior. Here, it
is necessary to choose a suitable mining method: less-structured work should be
analyzed by declarative process mining while structured routine work should be analyzed
by imperative mining methods. The resulting model of the composite process may
now be embedded into the surrounding process model.</p>
        <p>Consider the example from Figure 2. At the beginning, a process participant is
guided through a predefined process model, i.e., the workflow from step A to B, by
the process navigation system. Being on the brink of performing step B, the user, who
is an expert in his field, has the opinion that the abstract description of process step B
could be refined. Future process performers should benefit from a more detailed
description of the work to be done. This is why the user starts the PO interface where he
has the possibility to record his activities, in this case two atomic process steps C and
D, and preserve them for subsequent analysis. Finally, the user marks process step B
as completed and returns to the navigation interface where he continues the
predefined workflow. The above scenario covers a situation where existing models could
be refined by expert staff while performing the process. The described functionality
becomes even more useful, when we consider the application in the field. Here,
process participants frequently find solutions to problems on their own. This knowledge
should be preserved for future cases.
Until now the integration of PO and PN manifested in the specialization or extension
of already predefined models by observing the actual execution by the use of PO.
Therefore, the PN system invokes the PO system when needed. However, there are
also cases where predefined model parts can be used in free situations where process
execution is completely carried out only with support of PO, e.g., the observation of
whole processes that have never been modelled before. Here, users dynamically
instantiate processes from predefined templates, i.e., skeletons of process models
without any control flow information, and add newly occurring processes. In case that a
sub-process has already been modelled before, the available process model can be
executed with support of PN. Hence, the PO system invokes the PN system delivering
the process to be performed. On this way, process participants can leverage a full
WfMS in case of a predefined process model.
5</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>Related Work</title>
      <p>
        The most recent approach in the field of declarative process execution is the Declare
framework [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ]. It is based on linear temporal logic (LTL) and therefore allows for
relating process steps by temporal and existential constraints. These constraints may
not contain statements on data, agents or tools. The only way of relating the temporal
order of steps to these perspectives is to make the constraints depend on certain
conditions. Such a conditional constraint only applies if its condition evaluates to true.
Though a condition could then contain statements on data, agents and tools, the actual
constraint remains limited to temporal order and existence of steps. The other
perspectives cannot be constrained, which reduces the expressivity of the supported
process modelling languages. For execution, the LTL formulae of a process are
transformed into a finite state automaton which will then accept every trace of events that
complies with the formulae. In order to reach a technically feasible size of the
automaton, only the completion of a step is considered. Though a distinction between
optional and mandatory constraints is made in the theoretical preliminaries, distinct
modalities are not supported because only one automaton is generated for the
mandatory formulae. Both the LTL formulae and the automaton must be transformed and
reduced for necessary optimization reasons. Due to that, it becomes impossible to
draw a connection between the automaton’s transitions and the originally modelled
constraints. Therefore, Declare cannot support traceability during execution as the
proposed actions cannot be explained. In spite of the simplifications and reductions,
the LTL-based implementation of Declare suffers from scalability issues [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. Process
models of realistic size lead to large automata which have to be generated completely
before execution. There are several approaches that are very similar to Declare. In the
work of Sadiq et al. [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ] and also in the work of Wainer et al. [22], temporal
constraints like, e.g., serial, order and fork are used to relate steps. As for Declare, these
constraints may neither depend on nor influence perspectives like data, agents or tools
and modalities are not supported either.
      </p>
      <p>
        Adaptive Case Management (ACM) reflects a more flexible approach to
supporting work [
        <xref ref-type="bibr" rid="ref12 ref13">12, 13</xref>
        ]. Instead of predefining every possible process step or path, ACM
systems allow participants to dynamically instantiate processes from templates as well
as newly occurring processes when needed. There are already mature
implementations of ACM, e.g., [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ]. However, existing ACM approaches lack the use of recorded
information for guidance feedback and process model evolvement and the integration
with WfMS. A further process flexibility approach is the ADEPT framework [26] that
enables participants to dynamically change process definitions at run time. However,
the approach is still based on an imperative prescription of process models that is
often not suitable to describe less-structured processes. The work at hand provides an
approach to combine both worlds of process support. It relies on the recording, i.e.,
logging, of actually performed processes and the subsequent analysis of the
accumulated execution data. We already introduced an approach for manually generating
process execution data in [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ]. However, this solution was not operational enough,
since users where not supported, e.g., by providing process templates. Through the
integration of ACM-concepts, usability considerably increased. Latest pattern
recognition methods offer the possibility to extract complete process models [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ] that can
be deployed in WfMS. Van der Aalst et al. developed techniques and applied them in
the context of workflow management under the term process mining [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ]. There are
several algorithms that aim at generating process models automatically and focus
different perspectives of process data. Many of these traditional mining algorithms are
imperative approaches [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ]. These methods construct imperative models explicitly
showing all possible behaviours. Other ways to mine for process models are
declarative approaches. There are several declarative discovery algorithms like [
        <xref ref-type="bibr" rid="ref16">16, 23</xref>
        ].
      </p>
      <p>In cases where no complete process model could be extracted, workflow pattern
mining methods can be used to find unknown coherencies in process logs.
Representatives are sequence [24] or episode mining [25] that extract frequently occurring
fragments of processes. However, these methods are limited to the extraction of rules
considering the execution order of processes. Other types of process information, like
incorporated data or agents are neglected.
6</p>
    </sec>
    <sec id="sec-6">
      <title>Conclusion, Limitations and Outlook</title>
      <p>
        This contribution demonstrates how to support the full range from highly controlled
to fully flexible processes by integrating Process Navigation and Process Observation.
Previously modelled business process parts (usually office work) are executed by the
Process Navigation engine while unmodelled process parts (usually field work) are
supported and reconstructed by the Process Observation system. A drawback of
declarative models is that rule-based descriptions of processes generally are known to
suffer from understandability issues [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. One way of addressing this problem is to
continuously simulate the execution of a process model. Therefore, a further objective
is to develop a framework for the stepwise simulation of declarative process models
so that their behaviour may be completely understood. Discovering workflow patterns
using the Apriori algorithm may result in a high number of constraints. Many of them
are trivial like, e.g., the fact that the performer of a process step is always a person. A
future task is to reduce the number of constraints by identifying the trivial one.
      </p>
    </sec>
    <sec id="sec-7">
      <title>Acknowledgement</title>
      <p>The presented work is developed and used in the project “Kompetenzzentrum fuer
praktisches Prozess- und Qualitätsmanagement”, which is funded by “Europäischer
Fonds für regionale Entwicklung (EFRE)”.
22. Wainer, J., Bezerra, F.: Constraint-based Flexible Workflows. In: Favela, J. and
Decouchant, D. (eds.) Groupware: Design, Implementation and Use. pp. 151–158. Springer,
Autrans, FR (2003).
23. Chesani, F., Lamma, E., Mello, P., Montalo, M., Riguzzi, F., Storari, S.: Exploiting
Inductive Logic Programming Techniques for Declarative Process Mining. Transactions on Petri
Nets and Other Models of Concurrency II. 5460, 278–295 (2009).
24. Srikant, R., Agrawal, E.: Mining Sequential Patterns: Generalization and Performance
Improvements. 5th International Conference on Extending Database Technology (EDBT
’96). pp. 3–17 (1996).
25. Mannila, H., Toivonen, H., Verkamo, A.I.: Discovery of Frequent Episodes in Event
Sequences. Data Mining and Knowledge Discovery. 1, 259–289 (1997).
26. Dadam, P., Reichert, M.: The ADEPT project: a decade of research and development for
robust and flexible process support. Computer Science-Research and Development 23.2:
81-97 (2009).</p>
    </sec>
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