sensors found in smartphones are microphones,
cameras, accelerometers, gyroscopes,
magnetometers, pressure sensors, temperature
sensors, proximity sensors, light sensors, and
humidity sensors (Sztyler et al., 2015).
The multitude of information from these different
sensors is mostly processed within the background of
the smartphone (Sztyler et al., 2015). The user of such
a smart mobile phone will most commonly not see
this gathered sensor data. Instead, the data is mostly
used in order to maintain and assure the
functionalities of the device. The data is used, for
example, to recognise whether the smartphone is
being held to an ear. With this recognition, the device
is able to shut off the touchscreen, which in turn will
keep the user from performing unwanted actions.
A number of freely available applications give the
user of such a smart device the ability to see as well
as collect data generated by the in-built sensors.
One application like this is the Phyphox-App.
This app was created by the 2nd Institute of
Physics at RWTH Aachen University. The
application makes it possible to experiment with the
sensor technology built into the smartphone.
In addition to executing prefabricated
experiments for various applications, the experiment
editor allows one to create and execute ones own
experiments. The user is restricted solely by the
device's hardware (Rheinisch-Westfälische
Technische Hochschule (RWTH) Aachen and Staaks,
n.d.).
As stated in earlier chapters and sections, it is
possible to analyse and enhance previously
unmapped or incompletely mapped processes,
particularly tangible production processes within
small and medium-sized enterprises (SMEs), by
generating process data from sensors using process
mining (van der Aalst et al., 2012).
The overall aim of this research is to show the
possibility of such manual, locally bound processes
with which process data can be generated and
processed in such a way that it can be used in process
mining. The use of smartphones in this context is thus
identified as a possibility for processing data. Many
People or for that manner SMEs have smartphones at
their disposal. Thus, the idea arises to use these smart
devices and their sensory systems for the generation
of process data instead of trying to (if even possible)
integrate other sensory systems, often resulting in
high cost. By means of a smartphone and the
application Phyphox, it is possible to generate sensor
data on certain processes that are not otherwise
available due to various circumstances.
By generating this previously unavailable data, it
is possible to also consider these manual, locally
bound processes in process mining and hence reduce
the aforementioned blind spot of process mining and
generate added value for companies by analyzing and
improving the processes that could not be mapped
before (van der Aalst et al., 2012).
3.3 Extract Transform & Load (ETL)
The ETL process is often found in the context of the
two topics of business intelligence and big data or
data science and is thus also closely connected with
process mining. This is not surprising, as the ETL
process is used to extract large amounts of data from
different sources, process them, and then transfer or
load them in the required format into data
warehouses, databases, or other designated data
stores (Li, Kuang, and Liu, 2016).
The ETL process is an integral part of business
intelligence. The topic of business intelligence
describes procedures and methods for gaining
knowledge about aspects and facts within companies
(Dedi and Stainer, 2016, p. 225 ff.).
In addition to its use in process mining, the ETL
process performs essential duties. Typically,
unstructured, or partially structured data serve as the
beginning point in this context. Even in process
mining, the data foundation determines the outcome.
Additionally, the ETL process is used to extract
process data from various sources. The data is utilised
to prepare and transfer extracted data into systems for
further processing (Diba et al., 2019).
The ETL process consists of the three successive
phases of extraction, transformation, and loading. The
extraction phase includes the extraction and
sometimes combination of data in its raw form, which
is necessary for the subsequent acquisition of
knowledge. The sources from which data is extracted
can be very different in nature. The ETL applications
on the market can extract the required data from a
variety of different data sources. Due to the large
selection of data sources and their differences from
each other, the data is usually recorded in many
different types and formats (Du, Ye, and Wang,
2013).
In the subsequent transformation phase, the
extracted data is transformed or prepared in a way that
makes it usable for whatever purpose it is destined to
serve.
After the data is transformed, it can then be loaded
into a number of destinations, for example,
spreadsheets or databases.