=Paper= {{Paper |id=Vol-1439/paper12 |storemode=property |title=Mining the usability of business process modeling tools: concept and case study |pdfUrl=https://ceur-ws.org/Vol-1439/paper12.pdf |volume=Vol-1439 |dblpUrl=https://dblp.org/rec/conf/bpm/ThalerMAFL15 }} ==Mining the usability of business process modeling tools: concept and case study== https://ceur-ws.org/Vol-1439/paper12.pdf
Mining the Usability of Business Process Modeling Tools:
               Concept and Case Study

     Tom Thaler1, Dirk Maurer2, Vittorio De Angelis2, Peter Fettke1, Peter Loos1
 1Institute for Information Systems (IWi) at the German Research Center for Artificial Intelli-

               gence (DFKI) and Saarland University, Saarbrücken, Germany
           {tom.thaler,peter.fettke,peter.loos}@iwi.dfki.de
                 2Software AG, ARIS Development, Saarbrücken, Germany

            {dirk.maurer,vittorio.deangelis}@softwareag.com



       Abstract. Business process models are key artifacts in business process manage-
       ment. The technical support of the process of process modeling is important for
       the quality and the applicability of the resulting models. The quality of that tech-
       nical support plays an important role in the selection of corresponding software
       products and is a crucial characteristic of differentiation. Nevertheless, only little
       knowledge on the tool-specific line of actions and the corresponding challenges
       in the daily work of modelers is available, which makes it hard to improve a
       modeling tool against customer requirements. In order to address that conflict,
       we develop a method based on process mining, allowing the continuous analysis
       of modeling tools and the applied processes of process modeling with regard to
       software usability aspects. The resulting method containing the phases user mon-
       itoring, trace clustering, usage model derivation, usage model analysis, recom-
       mendation derivation and implementation primarily aims at a target-oriented de-
       sign and further development of business process modeling tools and is evaluated
       with the ARIS Designer by performing a user study. The results allow promising
       estimations for an application of the method in a broader context.

       Keywords: Business Process Modeling, Process Mining, Business Process
       Management, Lifecycle, BPM Use Case, ARIS


1      Introduction

Business process models are key artifacts in business process management. Tradition-
ally, process models are generated by human modeling experts using modeling tools
like the ARIS Designer of the Software AG. However, the process of process modeling
still has many facets to discover. In fact, there is already manifold research on the pro-
cess of process modeling like [1] describing a formal concept in order to study the
modelers’ sequence of actions or [2] investigating different modeling styles. However,
the corresponding papers focus on general procedures of modeling, while the adequacy
and the satisfaction of the technical support, which should be delivered with a particular
process modeling tool, is not considered. With regard to such usability aspects, that




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makes it hard to improve a modeling tool against end user needs. In the past, the Soft-
ware AG applied expert interviews, pre-release usability tests with pilot users of the
ARIS community and other established usability methods in order to improve their
modeling tool. However, only little knowledge on the challenges for the modelers’ daily
work could be identified and explicated.
    Against that background, in the context of a research project we were looking for
new approaches taking the real user behavior into account to be able to improve the
modeling tool based on the real and not yet identified customer needs. Hence, the paper
at hand aims at developing a method analyzing different dimensions of usability,
whereby both the system design (in terms of a technical support of the process of pro-
cess modeling) and the process of process modeling itself are explicitly addressed. Es-
tablished process mining techniques are used for an automatic derivation of usage mod-
els which can then be enriched by manifold data like GUI information (e.g. element
positions), or arbitrary user, system or context data (e.g. user experience). This renders
it possible to analyze the real user behavior in detail and allows the target-oriented im-
provement of the modeling process and the corresponding software design, especially
in terms of its usability. Referring to the general definition of software usability [3], the
term “business process usability” should, in this paper, be understood as the extent to
which a BPM software can be used for the effective, efficient and satisfactory manage-
ment of business processes.
    Since the potential method needs to combine different research fields from two dif-
ferent research disciplines, information systems (especially process mining) and soft-
ware engineering (especially human computer interaction and usability engineering), it
is necessary to identify the relevant literature from all fields involved. The identified
methods and techniques are analyzed with respect to their applicability in the context
of mining business process usability, which results in a collection of partial solutions
for specific problems and a collection of gaps. To fill these gaps, a design science re-
search approach is applied [4]. The approach of process mining is adapted with regard
to the specific requirements of usability engineering. A phase model was developed and
a corresponding tool support was implemented within the research prototype RefMod-
Miner 1. The resulting method is then evaluated in the context of a modeling scenario
with the ARIS Designer, Version 9, of the Software AG by performing a user study.
    After this introduction, Section 2 gives an overview of the related work in the men-
tioned research fields. Section 3 describes the developed method in the form of a con-
tinuous lifecycle, which is then applied in the context of the case study in Section 4.
The results and limitations as well as some possibilities for transferring the method to
other domains and application scenarios are discussed in Section 5. Section 6 gives an
outlook on future developments and concludes this work.




1   http://refmod-miner.dfki.de




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2      Related Work

As mentioned above, in the context at hand, the research field of usability engineering
as well as information system research in general and process mining in particular are
of major importance.
   Traditional methods measuring the usability of software are affected by manual and
empirical approaches often applying questionnaires, user or expert interviews and ob-
servations [5]. In fact, methods like eye-tracking or click-path-analyses are partially
automatable and literature concerning the application and design of such controlled ex-
periments in terms of using adequate test methods with a meaningful configuration (e.g.
sample size) is available [6]. However, the environment settings (e.g. laboratory) as
well as the data analyses are very expensive in most cases.
   Above all, there are some works using log data as a basis for the automated analysis
of software usability (e.g. [7, 8, 9]), which also contain approaches using event patterns
to measure specific aspects of usability (e.g. [10, 11]). Isolated works [12, 13] also
derive process models (petri-nets) and address some possibilities of usability analysis.
However, the used mining methods are rather rudimentary as they do not take today’s
aspects of process mining, like dealing with noise or a harmonization of log data of
different systems, into account. In fact, the used mining techniques cover the beginning
of the process mining era, e.g. [14, 15], and a further consideration of current methods
and techniques from the information systems research is missing.
   Nevertheless, process-orientation is a core characteristic of business (process man-
agement) software supporting concrete business tasks and processes in a technical man-
ner. Therefore, the application scenario of usability is of high importance for the infor-
mation systems research and for the design of business information systems in general.
Current approaches, e.g. genetic algorithms [16] or cluster techniques handling noisy
data or avoiding spaghetti-like models [17] could be helpful in that context. Not till
then, it is possible to derive meaningful models or meta-information enabling research-
ers or practitioners to draw concrete conclusions with reference to usability aspects.
Especially a combination of different process or model metrics from different research
disciplines – like those from [18] or [19] in the context of business process analysis and
from [20] or [7] in the context of usability engineering and usage analysis – might im-
prove the evaluation of business processes and their implementation. That metrics
makes it possible to quantify several aspects concerning the quality, the understanda-
bility and also the usability of business processes and their application in an automated
manner. In contrast to existing methods of usability engineering, there are also further
application scenarios like the automatic derivation and further development of software
reference models in general and usage models in particular [21].
   Indeed, both research fields address similar approaches towards an automatic deri-
vation of process models but the current states of research strongly diverge. A transfer,
adaption and further development of both states of research will imply an enrichment
of the respectively other discipline.




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3      Generic Concept Development

For the design of an adequate method and tool support, the approach of process mining
was adapted with regard to the specific requirements of usability engineering. A phase
model (Fig. 1) containing the phases user monitoring, trace clustering, usage model
derivation, usage model analysis, recommendation derivation and implementation was
developed and serves as a continuous lifecycle [22]. In contrast to previous approaches,
that lifecycle allows an application in the live operation and, thus, takes the real user
behavior into account. Therefore, mostly expensive laboratory experiments are not nec-
essary.

                                      user monitoring




                 implementation                           trace clustering




                 recommendation                             usage model
                    derivation                               derivation



                                       usage model
                                         analysis



                    Fig. 1. Business Process Usability Mining Lifecycle


3.1    User Monitoring

Process execution data (instance data) are the basis for business process usability min-
ing. Depending on the analysis objectives, there are different requirements for log data.
Generally, it is necessary to fulfill the traditional log data requirements of process min-
ing (case, task, originator, timestamp) [23], which should then be extended with addi-
tional information depending on the context. In case of an identification of usability
weak points, it might be helpful to log e.g. GUI information like element positions or
case-specific data. Collecting further information may imply the use of further data
sources like an enterprise database, external services or sensors. Since software-as-a-
service plays an increasing role in the business context, (web) server logs or error logs,
which are traditionally not considered in the context of process mining, are possible as
well. Against that background, one needs to design a logging strategy based on the
analysis objectives or the application scenario and implement it in the addressed soft-
ware. Furthermore, a consolidation of different data sources is of high importance.




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3.2    Trace Clustering
Trace clustering describes the task of clustering traces within log data concerning a
specific cluster criterion and is a traditional challenge in the context of process mining.
As, in general, business software as well as BPM tools cover a multitude of different
business processes, a corresponding log file covers all these processes, too. Discovering
a process model based on a non-clustered log file leads to a highly complex and non-
human-readable models in most cases (so-called spaghetti-like models). This makes it
necessary to identify different processes or instance classes in order to generate several
process models with less complexity or similar characteristics (e.g. [24, 25]). The
choice of a particular trace clustering technique thereby highly depends on the analysis
objectives [26]. Thus, there are manifold aspects, which may serve as a criterion for
trace clustering as e.g.:

• processes: e.g. variants, patterns, occurrence of loops or tasks
• resources/performance: e.g. time, budget, hardware, load values
• cases: e.g. value of a shopping cart
• users: e.g. experience, age, groups
• software: e.g. version, device

Thus, the recorded log data can be interpreted as a multidimensional data cube, whose
dimensions are partially not known a priori (see Fig. 3). In fact, some dimensions are
given by the log specification (the recorded attributes), others, like the actually recorded
process, are unknown. Against that background, it is partially possible to apply slicing
and dicing approaches from the area of data warehouses. However, especially in the
context of business process usability analysis, the identification of new information and
patterns regarding the proceeded processes and variants, possibly depending on user
profiles, are of major importance. A good overview of existing trace clustering tech-
niques with its corresponding implementations and an evaluation of their applicability
in different contexts is presented in [26].




                   Fig. 2. Illustration of cluster dimensions as a data cube




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3.3    Usage Model Derivation
Process mining distinguishes three different fields: (1) process discovery, (2) conform-
ance checking and (3) enhancement [17]. Process discovery aims at deriving a new
process model solely based on log data, while conformance checking addresses the
comparison of the as-is process to the to-be process. Enhancement focuses the deriva-
tion of new information from log data and annotating it to an existing process model.
   Against that background, all of the mentioned fields play an important role for busi-
ness process usability mining in general and in the phase of usage model derivation in
particular. In that phase, one needs to derive a process model based on the clustered log
data and to enrich it with further information like performance data, execution proba-
bilities, correlation matrices and further (scenario-specific) data and metrics. Today, a
lot of different process mining techniques with different characteristics of the output
models do exist already. They differ in the fitness and appropriateness of the resulting
models to the underlying log files, e.g. in their simplicity, in their abstraction level, in
the resulting model type (petri-nets, EPC, FSM, etc.) [27] or in their calculatory ap-
proach. Thus, a concrete algorithm should, again, be selected depending on the concrete
analysis objectives [e.g. 14, 16, 28, 29]. In contrast to discovery and enhancement, con-
formance checking should be seen in the phase of usage model analysis (phase 4) as,
especially in the context of business process usability mining, it might be of major im-
portance to know whether the users utilize a software in the intended way.


3.4    Usage Model Analysis

There are several possibilities of analyzing the usage model. First of all, many metrics
from different research fields exist and are able to characterize the model(s) and give
first indications to particular weak points:

• model metrics: e.g. complexity, extent, cross-connectivity [18, 19]
• process metrics: e.g. execution count, execution time, error rates, cancellation rates
• usability metrics: e.g. irrelevant actions, undo actions, using help function

These categories can also be broken down into further subcategories, e.g. size and com-
plexity in terms of model metrics or placement and time aspects in terms of usability
metrics. Disregarding these metrics, there are several further aspects, e.g.:

• Achievement of objectives / conformance checking: In the context of business pro-
  cesses and their management, oftentimes, there are objectives which should be
  achieved at process executions. These could be the overall execution time of a pro-
  cess, the consumption of resources, etc. Also business rules which are obligatory at
  the process execution, e.g. coming from legal aspects, might be important for the
  determination of conformance.
• Causal dependencies: Process models may contain causal dependencies between ac-
  tivities or process fragments, which are not evident in the process model. A correla-
  tion matrix may uncover those dependencies.




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• Core and exception fragments: Oftentimes, process models contain activities or frag-
  ments which are executed in a high amount of cases (core actions) as well as those
  which are executed very seldom (exception actions). Knowledge about that fre-
  quency helps focusing on the most important system points during development.
• Non-supported processes: Sometimes users use a system for the execution of pro-
  cesses which are not intended by the system producer. Identifying these processes
  helps improving a system against customer needs or may help identifying further
  business areas.
• System avoidance: Apart from the use of a system for non-supported processes, us-
  ers also avoid systems at executing particular process steps. Avoiding a functionality
  although it is available may be an indication of a non-working or badly implemented
  functionality.

In a nutshell, simple statistical indicators might lead to a first hint concerning process
or software usability issues but are not able to analyze these issues in detail. In most
cases, further information on the process and its execution logs is needed, which bases
on input from human experts.
   Since it is not possible to calculate the mentioned metrics from the different areas on
scratch, we implemented a tool support in the research prototype RefMod-Miner. An
extract of the available metrics and statistical analysis techniques are illustrated in the
screenshots presented in Fig. 5. Furthermore, it is necessary to have additional func-
tionalities allowing the graphical navigation through the model, like the visualization
of predecessor and successor nodes of a specific node or the highlighting of particular
nodes (like help or undo calls). The application of these analysis techniques may lead
to concrete hints to weak points in the technical support of modeling.


3.5    Recommendation Derivation

The recommendation derivation phase aims at interpreting the usage model analysis
results and delivering concrete hints concerning the business process and software us-
ability improvement and the further development of the system according to the real
customer needs. The recommendation should help the system producer answer e.g. the
following questions:

• Are there weak points in the system concerning the process support (e.g. avoided
  functionalities, needless undo-actions within process execution, misuse of function-
  alities, missing functionalities, unclear labels, very seldom or unsed buttons/func-
  tions at prominent positions, long loading times)?
• What are the core application scenarios at the user side? / Which implemented pro-
  cesses or functionalities are not used?
• Are there observable user profiles apart from user role or experience? Are there sig-
  nificant differences in using a system?




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       Fig. 3. Extract of metrics and analyses tools implemented in the RefMod-Miner

• Are there observable case profiles for a process influencing its execution?
• Are there further functional requirements at the user side?
• Are there possibilities to improve the process (e.g. user- or case-sensitive processing,
  adding new functionalities, data preloading, reorganization of forms)?
These questions should be answered based on the usage model analysis results. In fact
the results deliver hints to (potential) critical points of the usage models. However, there
are currently no adequate technologies making it possible to answer these questions in
an automated manner. Instead, expert knowledge is needed to interpret the analysis re-
sults and to derive concrete improvement capabilities.

3.6    Implementation

The implementation phase covers the selection, design, planning and implementation
of possible solutions for the generated hints and solution capabilities. Thus, this phase
acts as a completion of a particular lifecycle iteration and leads to a new software re-
lease. At the same time, it marks the beginning of a new lifecycle iteration




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4      Case Study

4.1    Design and Setup
The presented lifecycle approach should now be instantiated and evaluated by applying
it to a real world scenario. Against that background, we performed a user study in a
modeling scenario. 13 students needed to (1) model an organigram, (2) model an EPC
and (3) modify an EPC using the rich modeling client of the ARIS Designer of the
Software AG based on natural language text descriptions. The focus of the study was
to gain knowledge on how users act to reach a solution, not the correctness of the pro-
duced solution itself. Against that background, the interactions of the users were tracked
in a specific way, which is described below. 10 of the students already had modeling
experience, while the other 3 had not. The average time needed for executing the tasks
was 47 minutes. In order to be able to validate concrete business process usability issues
derived from the proceeded analyses, additionally, the user screen was recorded by a
screen capturing software.


4.2    Application and Findings
User Monitoring. As a first step and prior to the actual user study it was necessary to
develop an adequate logging strategy collecting the relevant information to be able to
generate detailed knowledge on how the users interact with the system in the context
of process modeling. Thus, in addition to the traditional log information of process
mining (caseid, task, timestamp and initiator) two further attributes, namely the callitem
describing in which way the user triggers particular actions, e.g. with the mouse, using
a shortcut, using an item of the symbol bar, etc., and the involved objects as e.g. the
elements on the grid are recorded as well. A sample log file generated by the ARIS 9
Designer in the user monitoring phase is presented in Fig. 2.




               Fig. 4. Sample log file generated in the user monitoring phase




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Trace Clustering. Since the user study contains three different exercises, in the trace
clustering phase we initially focused on separating the log file based on the processes
which are equivalent to that exercise. Prior to the clustering, we knew that the each of
the exercises contained actions which are in all probability not proceeded in the two
others. Referring to [26], we used that known causal dependency as a basis for separat-
ing the log file. As a second direction, we separated the log file based on the information
of whether a user has experiences in working with ARIS or not.

Usage Model Derivation. In order to derive the usage models based on the clustered
log files, we applied the Heuristics Miner [29] with default parameters. Thereby, the
log files were additionally prepared in two different settings: (1) task, callitem and ele-
ments are consolidated and use a task description, e.g. “place event ‘Event’ by
HOTSPOT_SYMBOL_BAR” and (2) the task is used as it is recorded, e.g. “place
event”. Extracts of the resulting EPC models from the two settings are presented in
Fig. 4. One can easily see, that the complexity of the models differs in a high degree,
which is grounded in the fact that setting 1 produces much more detailed node labels
and, thus, a significantly higher absolute amount of nodes than setting 2. Hence, the
degree of the proceeded task description consolidation again depends on the analysis
objectives.




         Fig. 5. Detailed vs. abstract usage model visualized with the RefMod-Miner

Usage Model Analysis. Analyzing and interpreting these models by applying the anal-
ysis functionalities of the research prototype RefMod-Miner led to the identification of
manifold aspects, ranging from a purely technical to a professional perspective. Three
of them are exemplarily presented in Fig. 6.
   The first example shows that users were not able to understand the toggled-edge-
mode. When activated, they expected an automatic connection of edges based on the




                                            161
element positions which led to the effect that modelers e.g. placed connectors over the
edges connecting several nodes. In contrast to their expectations, the connector was not
automatically connected.
   The second case covers a more professional aspect. Some modelers placed organi-
zational units to the grid and connected them to an activity. They expected the connect-
ing edge to be undirected, however, the system automatically produced a directed edge
from the organizational unit to the activity. The only solution to the arisen problem was
the manual deletion of the edge direction for all corresponding edges. A similar case
showed that it was not possible to modify, respectively change, the edge direction,
which might be meaningful in many contexts.
   In contrast to that, the third case uncovers different strategies in modeling. While
some modelers placed the nodes and labeled them immediately, others primarily added
a set of nodes and labeled all of them afterwards, which needs much more time.




                        Fig. 6. Presentation of three identified issues

Recommendation Derivation. The first issue results from the fact, that users were not
able to interpret the meaning of the “toggled-edge-mode”. Thus, renaming the func-
tionality might improve the understandability of it. In contrast to that, the second issue
constitutes a bug, which can simply be fixed by allowing the modification of edge di-
rections. Since the third issue uncovers a user demand (respectively a not yet considered
modeling strategy), it is necessary to provide a new functionality supporting that strat-
egy. A continuous labeling in the placement order might be a meaningful feature for
that specific demand.




                                             162
Implementation. For some of the identified issues, improvement potentials were de-
veloped and already planned for the implementation phase of the next software release,
which is currently worked on.


5      Discussion

Despite the early stage of studying and applying the approach in a real context and
although the number of participants in the user study was small, as well as the consid-
ered scope in the software, it was possible to identify 10 different issues ranging from
minor bugs and general weak points to specific user demands. Also the derived infor-
mation were detailed enough to be able to describe them in a professional way and to
address them with concrete improvements which are currently being implemented. This
shows the promising potentials for an application of the approach in a broader user
study with pilot users and beyond.
   However, there are also some aspects in the context of the case study, which should
be discussed. Although the achieved results are promising, the statistical relevance of
the particular identified issues and user demands is currently unknown. In the context
of a further study with more participants, it would be necessary to determine the statis-
tical relevance with statistical tests, e.g. using the p-Value.
   From a technical point of view, the possible amount of upcoming data will require
the use of methods which are able to handle it. Depending on the degree of detail of the
log files (e.g. every click, every mouse movement, etc.), on the number of monitored
users and on their intensity of use, the log files will become very memory-intensive.
Thus, their content will become more complex, as the proceeded case study has already
elucidated. This leads to several challenges as e.g. the user tracking, the clustering of
the log files and a potentially high complexity of resulting usage models, which are
hard to interpret by human experts. However, first methods and techniques addressing
these challenges do already exist and need to be evaluated with regard to their applica-
bility in the context at hand.
   Generally, one might ask the question of whether it is expedient to improve the usa-
bility of software tools supporting the process of process modeling as opposed to train-
ing the end users. In fact, an adequate training might help the users to work more effi-
ciently, effectively and satisfactory with a modeling tool, however, individual ap-
proaches of process modeling are important as well. Against that background, it is nec-
essary to do both, train the end users and improve the usability based on the end users’
needs. Additionally, it should be evaluated whether the user training or the software
improvement leads to more promising results regarding business process usability, e.g.
in terms of efficiency, effectiveness, satisfaction and also costs, which is an important
factor especially for small and medium enterprises. We assume that the cost factor is a
particular major strength of the developed method.
   With regard to the transferability of the developed method to other domains and ap-
plications, we identified manifold promising potentials. Thus, not only in the context
of process modeling, also in the context of business process supporting software in




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general, as e.g. ERP or workflow systems, an application of the developed method
might be promising in different scenarios. In addition to the already mentioned objec-
tives, the identification of end user needs and the analysis of the business process usa-
bility, we identified, amongst others, the following application scenarios [22].

• Controlling the Software Evolution. Further development of a software is in the na-
  ture of a product lifecycle. Nevertheless, it is challenging to evaluate whether a fur-
  ther development leads to the desired effect and whether it is used as it is intended.
  This affects both new supported processes and adapted existing processes. Since the
  developed method analyzes the real user behavior, it is possible to follow the soft-
  ware evolution from the user side. This can also be seen in [30].
• Inductive Usage Reference Model Development. Information about the process per-
  formance, the resource consumption and other collected data allow the inductive
  development of reference models with best practice (as known) character. Based on
  the process instances, a process model could be derived concerning different objec-
  tives like the minimization of cost or resources or the optimization of the output
  quality.
• Ease of Learn. One quality criterion of a business process supporting software might
  be the effort necessary to be able to operate it in an adequate manner. An analysis of
  the usage models of users over time would visualize their learning effects and, thus,
  allow the derivation of individual learning curves.


6      Conclusion and Outlook

The paper at hand presents a method for mining the usability of business process mod-
eling tools based on process mining. It constitutes different aspects, which need to be
investigated in order to be able to gather hints on the further development of a corre-
sponding software according to the real customer needs. While the phases of user mon-
itoring, trace clustering and usage model derivation already have an established theo-
retical and technical foundation which can be adapted concerning usability aspects, a
detailed analysis of the resulting data seems to be challenging. In fact, there are several
ideas quantifying the usability of a software system and characterizing process models.
However, these ideas need to be further developed, conceptualized, implemented and
evaluated.
   We were able to show that the developed method creates the missing link between
the software engineering view and the process-oriented view on business process sup-
porting software. This leads to promising potentials for their design and further devel-
opment. Moreover, several promising scenarios for a meaningful application of the
method in other domains could be identified and will be addressed in future work.
   Finally, the developed method has several advantages over existing approaches. It
can be applied in production use and in real environments and, thus, involves the real
user behavior. At the same time, it obviates a deformation of measurement results,
which traditionally constitutes a problem of direct observations. Moreover, the meas-
urement and analysis of usability aspects can, in many cases, be arranged automatically




                                           164
or with only little input, which leads to significantly lower costs and, thus, also enables
small and medium enterprises to apply the method.


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