Incorporating Ideas from Search and ETL into Process Mining
Jon Espen Ingvaldsen and Jon Atle Gulla
Department of Computer and Information Science, Norwegian University of Science and Technology (NTNU)
Sem Sælands vei 7-9, NO-7491 Trondheim, Norway
Keywords: Search, Process Mining, Business Process Intelligence, Decision Support Systems, ETL.
Abstract: Search is the process of locating information that matches a given query. Extract, Transform and Load
(ETL) editors provide a user friendly and flexible environment for creating operation chains and digging
into and explore data. In this paper, we describe the implementation of a process mining framework, the
EVS Process Miner, which incorporates ideas from search and ETL. We also describe two industrial cases
that show the value of applying search and graphical operation chain environments in process mining work.
The goal of process mining is to extract knowledge
from event logs recorded by information systems
(Aalst & Weijers, 2005).
Figure 1 show the phases involved in a typical
process mining project. The basis for all phases is a
data material that contains event related information
fragments. To make use of the raw data material,
pre-processing activities are often required before
process mining algorithms can be applied. The
output of the pre-processing phase is process or
event instances that can be explored through graphs
and process- and data mining models. The goal of
the exploration phase is to give the user a deeper
understanding of his business, which again can be
exploited to improve organizational structures and
Process InstancesProcess Instances
Figure 1: Phases of a process mining project.
To gain a proper business understanding, a
typical process mining project has to extract models
that focus on different aspects of the business flows
(i.e., control flow (Aalst, et al., 2004), (Weijters, et
al., 2007), load distributions (Ingvaldsen & Gulla,
2006), (Ingvaldsen, et al., 2005) and social networks
(Aalst, et al., 2005), (Song & Aalst, 2007)) and dig
down and investigate subsets of the data.
An important aspect of the process mining
projects is that for each phase it might be necessary
to return to the previous phase to make
improvements or perform additional activities. This
makes the nature of process mining projects iterative
and interactive. In this paper, we discuss how the
exploration phase of process mining work can be
supported with search operations and handled in an
Extract, Load and Transform (ETL) inspired
Use of search is a simplified yet sophisticated
way to gain access to the wealth of information
exists in event log related data repositories in
Enterprise Resource Planning (ERP) systems. By
search, we mean an information retrieval system
where data objects are serialized and stored in a
search index structure. By forming queries of
keywords, users can retrieve relevant information
without requiring much knowledge about underlying
data structures.
ETL editors, on the other hand, enable users to
compose chains of relevant operations to dig into
and work with the data and construct valuable
outputs. The operation chains can be edited
Espen Ingvaldsen J. and Atle Gulla J. (2008).
EVS PROCESS MINER - Incorporating Ideas from Search and ETL into Process Mining.
In Proceedings of the Tenth International Conference on Enterprise Information Systems - AIDSS, pages 340-347
DOI: 10.5220/0001716203400347
graphically, and it is easy for the user to replace
operations and modify how they are related.
By combining search and ETL inspired editors
for composing operation chains, a process mining
worker gets an explorative and easily customizable
environment for investigating executed events and
process instances. In this paper, we describe a
process mining framework, the EVS Process Miner,
which integrates search and graphical operation
A description on the EVS Process Miner is given
in Section 2. Section 3 describes two industrial cases
that show the value of combining search and
operation chains in process mining. Section 4
discusses challenges related to search in process
mining projects and alternative solutions. Related
work is given in Section 5, followed by a conclusion
in Section 6.
EVS Process Miner is a plug-in based framework for
mining business process instances. It is a part of the
Enterprise Visualization Suite (EVS), which is
developed by Businesscape AS in cooperation with
the Information Systems group at NTNU. EVS is a
family of process mining related applications and the
motivation behind the whole framework is to
A framework that targets process mining of
SAP transactions and the magnitude and
diversity of transaction logs in SAP
Process mining of process instance logs
that are enriched with substantial amounts
of context information.
Figure 1 shows an overview of the EVS
architecture. EVS contains a pre-processing module,
named EVS Model Builder, which supports
extraction of process related information fragments
from SAP transactions and constructs process
instance information objects are serialized and
stored in a Lucene based search index (Ingvaldsen &
Gulla, 2007). This search index forms the basis for
EVS Process Miner and the search operations
presented in this paper.
When designing the EVS Process Miner, we
were inspired by the flexible work environment
provided in ETL editors. ETL is a process in data
warehousing that involves extracting data from
outside sources, transforming it to fit business
needs, and ultimately loading it into the end target,
typically a data warehouse (Karel, R.,
2007)(Chaudhuri & Umeshwar, 1997). An operation
processes a set of input objects and offers an output
object, which is available for further processing by
other operations. Most ETL tools consist of a
graphical editor where the user can insert operations
and simply drag input-output dependencies between
Figure 2: EVS architectural overview.
The core of the EVS Process Miner is an empty
framework for creating chains of operations and
serializing operation properties. The framework is
constructed such that operations are accessed as
plug-ins through defined extension points. This way,
it is easy to extend the application externally with
new operations. The plug-in architecture is based on
the Eclipse Runtime and the Open Services Gateway
initiative (OSGI) framework
An operation in the EVS Process Miner consists
of programming code for processing inputs and user
interfaces for settings property values. One of the
implemented operations is search. It requires an
available Lucene index with process instance related
information as input, contains a user interface for
specifying a query, and provides an iterator with
search results as output. In addition to this search
operation, the EVS Process Miner contains
operations for visualization, data export, data
transformation and extraction of data mining
EVS PROCESS MINER: Incorporating Ideas from Search and ETL into Process Mining
Figure 3: Example of the data structures stored in the search index.
EVS structures business transaction data
according to an underlying business process
ontology that includes the following concepts:
Event objects: A happening at a point of
time. An event object typically consumes a
set of resources to produce outputs. An
event object contains a timestamp and
relationships to business objects that were
involved in the event and form its context.
Business objects: Domain entities. Business
Objects contain a unique identifier and a
Process: “the set of partially ordered
process steps intended to reach a goal
(Feiler & Humphrey, 1993).
Process Instance: a chain of event objects
that depend on each others output
resources. The event objects in an event
chain are ordered by their timestamp
Properties: Descriptive attributes which are
valuable for our analyses. A property
contains a name, a value and a description
of its data type (categorical, numerical or
Process instances, and event and business objects
contains a key value that uniquely identify them.
Event and business objects contain also a reference
to their type descriptions.
Figure 3 shows an example of such process
instance related information objects from a SAP
environment. The process instance with the unique
id 0000001 contains three events. Each event has a
relation to a transaction business object that contains
a description of the activity carried out. As we can
see, the process instance is initiated by the creation
of a purchase requisition, followed by the creation
and change of a purchase order. Two different
users, Andy Smith and Per Hansen, are involved in
the process instance and both belong to the same
department. Both the purchase requisition and the
purchase order contain two items. The items of the
purchase order are enriched with categorical
property that provides a textual description of the
ordered products. A categorical property is also used
to provide vendors with region information.
ICEIS 2008 - International Conference on Enterprise Information Systems
2.1 Process-aware Search
Traditionally, search applications assume documents
to be unstructured and construct indices on the basis
of normalized frequency counts like tf.idf for all the
terms that appear in the document set. In this
particular process mining case, we have structured
log information that can help us interpret and mine
the organization’s business processes. The
representations can help us construct structured
indices of process instance-related data fragments,
provided that we can transform them into a format
that is understood by the process mining application.
The approach taken is to annotate process
instance data with ontological information that
interprets the data with respect to our underlying
business process ontology.
To make the process instance related data
fragments searchable, each object is serialized as a
set of strings. The set of string fields are set to
enable detailed queries from the advanced users, and
they contain all data necessary to reconstruct Java
objects and their internal relationships. The index
contains four fields:
1. key: Contains a unique identifier value for
each entry. This field can be included in the
query when we want to retrieve exactly one
known entry.
2. type: The index contains entries for events,
business objects and process instances. The
type field can be specified to filter out only
entries of a certain type in the result set.
3. path: This field contains a ordered list with
the name of each event in a process
instance. It is used to retrieve process
instances that contain a certain event
4. timestamp: This field contains timestamp
information for event entries. This field is
useful for filtering out entries within a
certain period of time.
5. data: This field contains all data necessary
to reconstruct Java object representations
and relate the objects to each other. This
field makes it also possible to search after a
given business object, like a vendor, and get
all events or process instances for where this
business object is related.
Below follows an example of how the process
instance from Figure 3 would be represented as a set
of searchable strings.
key: 000001
type: Process Instance
path: Create Purchase Requisition >
Create Purchase Order > Change
Purchase Order
timestamp: <NULL>
data: eventchain {
events {
event {
type {
Create Purchase Requisition
id {
type = Create Purchase
Requisition; cdhdr.changenr
= 009009931002;
timestamp { 1180994400000 }
rels {
rel {
reltype { output }
business object {
type {
Requisition }
id {
type = Purchase
= 03003211;
value {03003211}
rels { …
Note that the data string in the example is
shortened and describes just a subset of the related
event and business objects.
A detailed query is a query where the user
targets specific fields in the index. One example of
such a query is
path:”Create Purchase Requisition >
Create Purchase Order”
Such a query would result in hits for all entries in the
index where parts of the path field contain a “Create
Purchase Requisition” followed by a “Create
Purchase Order”.
These ontology-driven search operations allow
us to retrieve, aggregate and interpret process
instance data in accordance with a unified semantic
model of business processes. This unified model –
the ontology – makes sure that all EVS components
understand the data in the same way and provides
the standardized terminology needed to add new
components later.
EVS PROCESS MINER: Incorporating Ideas from Search and ETL into Process Mining
Figure 4: Operation chain that both visualizes data in a scatter plot and exports MXML.
Figure 5: An operation chain that uses a split and merge of output data to achieve the final decision rules.
In this Section we will describe two scenarios that
show the value of applying search and operation
chains in process mining projects. EVS Process
Miner has been tested out in a process mining
project on SAP data at a Norwegian medium sized
company. The scenarios in this section are based on
the scope and findings from this project.
3.1 Case 1: Detailed Analysis of Sub
The user, a process owner, needed an assessment of
how the purchase processes are carried out. The
process that he wanted to investigate included the
activities “create purchase order and “goods
receipt”. Although the process owner has good
knowledge about this process, he needed AS-IS
models that describe which activities are actually
used, how the loads are distributed, and how the
activities depend on each other. He also wanted to
investigate how much time each department spends
on completing this process.
To carry out the investigations, the process
owner composed an operation chain as shown in the
editor screenshot in Figure 4. The initial operation
contained property values for accessing a Lucene
index with process instances, events and business
objects. The following search operation was
specified with the query:
+type:“Process Instance”
+“create purchase order”
+“goods receipt”.
In Lucene, the plus sign means that the following
term must occur in the result set entries. The result
set of this search contained process instance objects
from the string representations in the index that
matched the query phrases. The result set was used
to construct both a dataset and a MXML file.
Datasets are created to form a basis for statistical
analysis, data mining and visualization. The dataset
builder operation identifies a large set of potential
attributes based on the search result information.
The user can then select a subset of attributes that
should be included in the dataset. In our simplified
scenario, the process owner selected department-
name and the duration between create of purchase
ICEIS 2008 - International Conference on Enterprise Information Systems
order and goods receipt as attributes for further
analysis. In the final operation, the dataset was
visualized as a scatter plot.
In such a scatter plot, the process owner can see
how long time each department spends on the
processes and he can compare their performance. As
every single process instance is scattered, the
process owner also gets an overview of variances
and loads for each department.
MXML is the import format for ProM (Dongen
& Aalst, 2005). ProM is an open source process
mining framework that contains plug-ins that focus
on extraction of different models, i.e., Petri-Nets,
EPC, Heuristic Networks, Social Networks, etc. A
screenshot of an extracted model using the Fuzzy
Miner plug-in is shown in Figure 6. Using such a
process mining tool, the process owner can mine the
data and visually see all the involved activities in the
purchase process, how often they are executed and
the relationships between them.
Figure 6: Screenshot of control flow models extracted by
the Fuzzy Miner plug-in in ProM.
3.2 Case 2: Analysis of Alternative
Process Flows
The process owner recognized in the ProM models
from Scenario 1 that the purchase process also
contained the activity “Receive Order
Confirmation”. However, in the ProM models, the
process owner could see that large amounts of
purchases were done without getting an order
confirmation from the vendors. This annoyed the
process owner and he wanted to know which
vendors, departments and products that are
frequently involved when no order confirmation is
The process owner wanted to create and analyse
a dataset with process instance entries that are
labelled with information about whether an order
confirmation was received or not. To carry out the
investigations, the process owner modifies his
operation chain, shown in Figure 5. As for Case 1,
the initial operation offers a search index with
process instances, events and business objects. As
the process owner wanted to investigate process
instances for where the activity “Receive Order
Confirmation” occurs vs. those where the activity is
not involved, he created two search operations. The
first search operation has the query:
+type:“Process Instance”
+“receive order confirmation”.
The second search operation has a query which is
similar, except that the pluss sign in front of
“receive order confirmation” is changed with a
minus sign. In the Lucene query language a minus
sign in front of a term is used to specify that term
should not occur in the results. The search
operations are followed with operations that
construct a dataset based on the result sets. In these
operations the set of interesting dataset attributes is
also selected. In our case, the process owner selected
the attributes vendor, department, and product. The
rows of the two available datasets are merged
together. The output of the merge operation is a
single dataset where each row is labelled with the
name of its origin dataset. The labelling is added as a
separate attributes, named class.
An example with entries from such a merged
dataset is shown in Table 1. Here, we can see the
three selected attributes and a class attribute
containing the names of the original datasets. The
merged dataset is provided as input to a decision rule
operation that identifies significant IF – THEN rules
that describes the class attribute and its values.
Table 1: Example entries from the merged dataset.
Vendor Department Product Class
Oslo Cacao
300 kg
Oslo Sugar
100 kg
Bergen Palm
The industrial cases described how the process
owner approached the process mining task. The
graphical editor enabled the process owner to
compose operation chains that constructed MXML
and graphs that visualize how much time each
department spend on the process. Based on these
first findings the process owner could change parts
EVS PROCESS MINER: Incorporating Ideas from Search and ETL into Process Mining
of the operation chains and narrow the focus of
further investigations.
In the second case, search was used to retrieve
two alternative paths for executing the process. The
search results were converted to datasets that were
merged and analyzed. Investigation of alternative
process executions is not limited to process paths.
The same approach could also be applied to
investigate and compare process executions where
different vendors, departments, or other business
objects are involved.
Search provides a simple interface to business
process information. An alternative to search indices
and keyword queries is more traditional solutions
with database tables and Structured Query Language
(SQL) statements. Figure 7 shows a comparison
between keyword search, detailed search querying,
and SQL. By keyword search, we mean search
queries where the user only type a set of relevant
keywords that should occur in the result set items.
Detailed search querying, on the other hand,
addresses query terms in specific index fields. The
comparison involves the following aspects:
Data Access Simplicity: How quick and
easy is it to formulate a query?
Required Data Structure Knowledge:
How much knowledge about underlying data
structures is required from the user?
Result-Set Quality: To which extent is the
result-set matching the user request? Is the
user getting the information requested, and
how much of the result-set is relevant?
Figure 7: Comparison of alternative approaches for
accessing data sources: a) Data access simplicity, b)
Required data structure knowledge, c) Result set quality.
As visualized in Figure 7, the approaches that
require some background knowledge of the
underlying data structures also have the highest
result-set quality. However, in the user environment
there are trade-offs between the three dimensions. In
analysis work like process mining, we have users,
like process owners, that often possess limited
technical knowledge. As we want to explore the data
interactively, it is also a big gain if the user can dig
into and investigate perspectives and data subsets
quickly. In such settings, search is preferable. As the
technical knowledge of process mining users varies,
it is favourable if both simple keyword search and
detailed search querying is supported.
According to Forrester Research the leaders and
strong performers of the ETL market are IBM,
Informatica, Business Objects, Oracle, Ab Initio,
SAS Institute, Microsoft, IWAY Software, and
Pervasive Software (Karel, 2007). These software
vendors incorporate ETL as parts of their data
warehousing and business intelligence solutions.
Lately, these software vendors have given
considerable attention to enterprise search and
search engine technologies. Many ETL vendors have
purchased or established partnerships with vendors
of enterprise search solutions (Brown, 2006)
There are several motivations behind the
merging of the two areas. At one hand, search can be
applied to retrieve complete business intelligence
reports. On the other hand search can also be applied
in the process of investigating data and revealing
unknown patterns (Priebe & Pernul, 2003). Here,
search represents a paradigm shift in business
intelligence. The benefits of using search
technologies on structured data sets have been
emphasized by commercial companies like Fast
Search & Transfer and Autonomy Inc (Olstad,
2005)(Brown, 2006).
At an even more ambitious level, search can be
applied to formulate and answer questions directly.
Here, we require semantic understandings of both
user requests and data available (Gulla, et al., 2006).
Within several domains, efforts are done to integrate
semantics, in form of ontologies, in information
retrieval systems (Guha, et al., 2003). The
ontological information is used both to extend the
query language and annotate the contents of
available documents (Sheth & Ramakrishnan, 2003).
(Medeiros, et al., 2007) discusses several
directions for the development of semantic process
ICEIS 2008 - International Conference on Enterprise Information Systems
mining and monitoring tools. They point out that the
main opportunity provided by such systems is the
link between the event log structures and the actual
concepts they represent. This linking is achieved by
annotating the elements with concepts in ontologies.
Important here is also the fact that this ontology is
used throughout the process mining environment,
not just for the search operations.
This paper have shown how the exploration phase of
process mining work can be supported with search
and graphical editors for customizing operation
chains and working with the data. The practical
value of such an environment was demonstrated in
two industrial cases.
Search provides a simple interface to process
mining sources, without requiring extensive
knowledge about underlying data structures.
Graphical editors for operation chains make it easy
for the user to customize data processing chains and
find valuable outputs. Another nice property with
these editors is that for any final output the history
of involved data processing steps are visible and
By combining search and ETL inspired editors, a
process mining worker gets an explorative and easily
customizable environment for investigating executed
events and process instances.
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EVS PROCESS MINER: Incorporating Ideas from Search and ETL into Process Mining