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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Quality Assurance Aspects in Automation Systems Engineering Projects</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Dietmar Winkler</string-name>
          <email>Dietmar.Winkler@tuwien.ac.at</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Electrical Change Software Change P</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>ID Change</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>ID Change Electrical Change Software Change</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>FuncBtiloonck</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Christian Doppler Laboratory “Software Engineering Integration for Flexible Automation Systems” Institute of Software Technology and Interactive Systems, Vienna University of Technology</institution>
          ,
          <addr-line>Vienna</addr-line>
          ,
          <country country="AT">Austria</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Electrical properties, e.g., Transmission lines. Figure 1: Changes and Defects - Challenges in heterogeneous Engineering Environments</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Process Engineer</institution>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>Software (SW) properties</institution>
          ,
          <addr-line>e.g., Logical Behavior</addr-line>
        </aff>
      </contrib-group>
      <fpage>33</fpage>
      <lpage>40</lpage>
      <abstract>
        <p>- Automation systems, e.g., hydro power plants and industrial automation systems include heterogeneous engineering disciplines, e.g., mechanical, electrical, process, and software engineering, and raise additional challenges for quality assurance activities, e.g., identifying defects in change management processes where different disciplines are involved. Our observations in industry shows various tools and data models with limitations in collaboration and data exchange that hinder effective and efficient quality assurance across disciplines where experts have to collaborate and exchange data. The Automation Service Bus (ASB) offers a middleware platform with focus on (a) integrating tools from difference disciplines and (b) bridging the gap between data models coming from different sources. Based on technical and semantic integration quality assurance across disciplines and domain borders becomes possible. In context of quality assurance and project management this paper presents selected research challenges and shows results of implemented application prototypes of an ongoing project in industry context.</p>
      </abstract>
      <kwd-group>
        <kwd>Software</kwd>
        <kwd>Engineer</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Keywords-Quality Assurance, Automation Systems
Development Processes, Defect Detection, Integration Testing,
Project Management</p>
      <p>I.</p>
      <p>INTRODUCTION</p>
      <p>
        Large-scale automation systems engineering projects, like
hydro power plants, steel mills and large manufacturing
systems include heterogeneous disciplines during design and
development, construction and test, commissioning, and
operation [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ][
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]. During the product life-cycle [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] various
stakeholders from heterogeneous disciplines have to collaborate and
exchange data across domain-specific tools applying domain
specific data models [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. For instance, electrical engineers
focus on circuit diagrams and wiring, process engineers
provide process workflows for the plant, and software engineers
develop control system to observe and control the automation
system under construction. Our observations showed that
process engineers and domain experts focus on bridging the gap
between heterogeneous environments manually to support
development, commissioning (i.e., system launch at the
customers site) and operation (i.e., operation and maintenance at the
plant site). Note that these manual activities are error prone
(e.g., caused by media breaks) and require a high effort
provided by experts when linking various data models and sources
manually. Because of limited interaction and collaboration
support provided by individual tools (i.e., technical
heterogeneity) and various applied data models (semantic heterogeneity)
collaboration becomes more difficult and results in a high
manual effort for synchronizing data models during the
lifecycle phases [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]. Efficient automation-supported data
exchange across disciplines and domain borders is an important
key challenge to increase quality and decrease defects, effort
and cost.
      </p>
      <p>
        Quality assurance is a comprehensive activity across all
project phases to enable the construction of high quality
products. In addition results of quality assurance activities help
project and quality managers in identifying defects early [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ],
assessing individual project states frequently, and – based on
individual project states – enables product quality evaluation
with respect to monitoring and controlling the engineering
project [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. Nevertheless, loosely coupled tools and data models
hinder efficient quality assurance and require high manual
effort for data collection, aggregation, and analysis. As a
consequence, quality assurance tasks are executed less frequently
and can raise quality issues. Figure 1 highlights the need for
automation supported data exchange for change management
and quality assurance in heterogeneous engineering
environments.
      </p>
      <p>Mechanical &amp; process
properties</p>
      <p>
        Change Management (CM) is a success critical issue in
software and systems development projects during
development and runtime [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ]. CM addresses the need to respond to
changes coming from individual disciplines by other related
disciplines. For instance a modified sensor type (from the
electrical discipline) can require modified control flows (change
within the process discipline) and modified data visualization
approaches (software engineering discipline), e.g., modified
value ranges of the changed sensor. Changes have to be passed
to all involved disciplines within a short time interval to enable
addressing these changes within assigned individual models by
related engineers. Thus, change management is a crucial use
case for engineering projects and quality assurance. Quality
assurance focuses on identifying defects in general and in
change management processes specifically. Thus, we observed
three main challenges:



      </p>
      <p>
        Quality Assurance support for early defect detection in
engineering processes across domain borders [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ].
      </p>
      <p>
        Testing signal chains from hardware sensor to software
variable to address defects across disciplines in later
phases of systems development [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ].
      </p>
      <p>
        Comprehensive view on the project progress including
signal change observations and project course assessments
[
        <xref ref-type="bibr" rid="ref13">13</xref>
        ].
      </p>
      <p>The remainder of this paper is structured as follows:
Section 2 introduces to common automation systems development
projects and project dashboards with focus on quality assurance
and project management. Section 3 presents the research
issues. Section 4 presents candidate solution approaches
implemented at our industry partners. Finally, Section 5 summarizes,
presents lessons learned and highlights future work.</p>
      <p>II.</p>
      <p>RELATED WORK</p>
      <p>This section summarizes related work on (a) Automation
Systems Engineering (ASE) processes, (b) change management
in ASE projects, and (c) project management with project
cockpits/dashboards.</p>
    </sec>
    <sec id="sec-2">
      <title>A. Automation Systems Engineering Processes</title>
      <p>
        Lessons learned from business IT software development
show a variety of different software processes as framework
for project management support [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. Traditional software
development projects typically follow a sequential or V-model
approach (e.g., Waterfall Model and V-Modell XT1). A lack of
flexibility with respect to changes caused by customer requests
(e.g., frequent changing requirements) and/or defects lead to
the application of more flexible and agile process approaches,
e.g., Scrum [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ] or eXtreme Programming [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
1 See http://www.v-modell-xt.de for a detailed description of
the V-Modell for software and systems development projects.
      </p>
      <p>
        In automation systems development projects various
discipline apply heterogeneous tools and data models. Changes can
occur frequent (in different disciplines) and have to be
synchronized to enable a consistent engineering project. Our
observations in industry projects showed a traditional engineering
process approach following a (sequential) product life-cycle
process model. Figure 2 presents the basic process approach at
our industry partner – a large scale systems development and
integration organization – including six basic steps. The
individual process phases are organized strictly sequentially. A
major challenge is to synchronize various disciplines within
individual phases as often as possible to (a) identify defects
early, (b) enable efficient handling of changes, (c) enable a
consistent engineering repository involving artifacts from all
related disciplines, and (d) enable a comprehensive view on the
overall project progress. Today this synchronization is
executed mainly manually or in a less automated way [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ].
      </p>
    </sec>
    <sec id="sec-3">
      <title>B. Change Management Processes in ASE Projects</title>
      <p>
        Figure 3 presents the challenges of Change Management in
heterogeneous environments [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ][
        <xref ref-type="bibr" rid="ref22">22</xref>
        ]. Electrical engineers
perform changes in electric circuit diagrams including electric
planning tools and data models (1). Typically individual tools
are able to handle changes and quality assurance tasks
individually. Nevertheless, change management and quality assurance
across systems borders and tools are not sufficiently solved.
Changes have to be passed to affected engineers/disciplines to
enable efficient synchronization and defect detection (2). In
addition notification of changes (3) can support engineers in
better understanding the individual change and its
consequences, and – in case of conflicts – enable an efficient
problemsolving between involved engineers.
      </p>
      <p>Changes
1</p>
      <p>Electrical Plan</p>
      <p>Tool Data
Electrial Engineer</p>
      <p>Software Dev .</p>
      <p>Environment</p>
      <p>Tool Data
Software Engineer</p>
      <p>Pipe &amp;
Instrumentation</p>
      <p>Tool Data
Process Engineer</p>
      <sec id="sec-3-1">
        <title>2 Synchronization /</title>
        <p>Defect Detection
3 Notification</p>
        <p>
          In industry practice we observed less frequent
synchronization (because of a high effort by experts who a familiar with at
least two disciplines), informal discussions during
problem/conflict solving processes [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ][
          <xref ref-type="bibr" rid="ref22">22</xref>
          ] and quality assurance
tasks. Based on interviews with engineers with our industry
partners we learned that a set of defects are identified during
the start-up phase (commissioning) by introducing system
components stepwise (including on-site quality assurance
tasks). In addition we learned that common defects, e.g.,
missing links between (hardware) sensors and (software) variables
or defective component descriptions could have been found
earlier by applying a systematic and frequent synchronization
of different disciplines, systematic quality assurance tasks (e.g.,
by supporting focused reviews), and testing approaches [
          <xref ref-type="bibr" rid="ref25">25</xref>
          ] on
integration test level.
efficient quality assurance (i.e., focused reviews and
integration testing) and (b) project observation and control with the
Engineering Cockpit [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ].
        </p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>C. Comprehensive Project Management and Control</title>
      <p>
        Project and quality management, i.e., project observation
and control, are key activities of project and quality managers
across individual phases of systems development to capture the
current project state and introduce counter measures in case of
derivations in terms of resource problems and quality issues
[
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. Software cockpits [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] and software project control
centers [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ] have been developed to enable project and quality
management in business IT software projects. Main objectives
of engineering cockpits include (a) the collection of
engineering data, (b) the aggregation and analysis of the collected data,
and (c) the presentation of the analysis results according to the
need of project and quality managers [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ][
        <xref ref-type="bibr" rid="ref16">16</xref>
        ]. Nevertheless,
heterogeneity of engineering disciplines, tools, and data models
include an additional challenge in establishing a
comprehensive view on an automation engineering project.
      </p>
      <p>Because of less transparent changes in automation system
engineering projects (due to less frequent synchronization
between disciplines and limited data exchange capabilities),
changes and the impact of changes remain unclear and depend
on the individual estimation of experts, i.e., project and quality
managers. A key question of project managers focuses on the
number of changes in an engineering project per time interval,
project phase and the impact of/on disciplines raising changes
and/or defects.</p>
      <p>III.</p>
      <p>RESEARCH ISSUES</p>
      <p>Based on observations and discussions with our industry
partner we identified a set of research questions:</p>
    </sec>
    <sec id="sec-5">
      <title>RQ1: How can we enable data exchange between heterogene</title>
      <p>ous data sources? Efficient data exchange between tools and
various data sources is the foundation for efficient change
management, quality assurance, and project management.
RQ2: How can we enable efficient quality assurance across
disciplines? Individual quality assurance activities are located
within the individual discipline and tool. Today, these quality
assurance tasks are executed by experts, who are familiar with
at least two disciplines and requires a high effort. Automation
supported QA across disciplines can increase QA efficiency
and product quality.</p>
      <p>RQ3: How can we enable a comprehensive view on the
engineering project? Traditional project management approaches
focuses on an isolated discipline within homogenous
environments. We observed limitations in heterogeneous environments
involving loosely coupled tools and data models in various
disciplines. One key question is how we can develop a project
cockpit to address cross-disciplinary engineering projects.</p>
      <p>IV.</p>
      <sec id="sec-5-1">
        <title>USE CASE AND INDUSTRY PILOT APPLICATION This section presents the key use case “Change Management” [22] and the pilot application at our industry partner to enable data exchange across disciplines as foundation for (a)</title>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>A. Automation Service Bus and Common Concepts</title>
      <p>
        The Automation Service Bus (ASB) has been developed as
a middleware platform [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] to bridge the technical gap between
various tools and the semantic gap between individual data
models [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Technical and semantic integration of tools and
data models are the foundation for comprehensive quality
assurance and project monitoring and control.
      </p>
      <p>
        Figure 4 presents the common concepts [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] represented as
the virtual common data model (VCDM), aiming at bridging
the gap between various and heterogeneous sources [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. The
main idea is focusing on common data sets that enable the
collaboration of related disciplines. For instance, electrical
engineers apply dedicated tools for constructing electrical plans (1);
on the other hand side software engineers apply tools (5) for
modeling software functionality, e.g., function plans (common
graphical language for implementing control applications).
Common concepts (3) located in a centralized data base – the
engineering data base (EDB) – holds data which are relevant
for both disciplines for synchronizing and collaboration
purposes. Note that the common concepts are limited to a small
number of data elements which are mandatory for
synchronization. Other tool-specific data (not required for synchronization
steps) are left within related individual tools. Data changes are
passed and synchronized via transformers (T) to and from
related disciplines in a bidirectional way (see (2) and (4)). Thus,
this concept enables data exchange across different tools using
different data models.
      </p>
      <p>Virtual common data model
Tool A Data Model Tool A Data Extract Tool B Data Extract</p>
      <p>Electrical Plan T</p>
      <sec id="sec-6-1">
        <title>Electrical CusTt_oSoilgDnaatla 2</title>
        <p>Engineer1 -+++++-VVDAD-aoiedg-llsdtuiatc-rel/gerA-ieRspn-satainloognge -+X-.-. - --+Y---.-. - - -
Tool B Data Model
T Function Plan</p>
      </sec>
      <sec id="sec-6-2">
        <title>4 FB_SignTaololData</title>
        <p>5 -++-LF-oB-c_a-Int-ifoo-n
-+FA-.-. - - - - +++IVDnaapltuuatetyDpeefs -+FZ-.-. - - -</p>
        <p>Software</p>
        <p>Engineer
3</p>
        <p>Engineering Data Base</p>
        <p>
          Analyzing typical data models used in hydro power plants
at our industry partner, we identified signals as underlying and
common concepts linking various disciplines [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. For instance,
electrical engineers see signals as wires and measurable voltage
levels, process engineers identify signals as input/output values
of pipes and valves, and software engineers see signals as
software variable used to control and visualize data within the
control application. Thus, signals (as common concepts)
represent a light-weight conceptual approach that can enable
efficient collaboration of various disciplines and enable efficient
data exchange and synchronization between heterogeneous
engineering environments.
        </p>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>B. Synchroniation between Various Disciplines</title>
      <p>
        Figure 2 presented a basic engineering process for
constructing large-scale automation systems, i.e., hydro power
plants, observed at our industry partner. Frequent
synchronization of engineering artifacts (across tools and data models) can
increase construction efficiency, increase quality, and reduce
cost [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ][
        <xref ref-type="bibr" rid="ref25">25</xref>
        ].
      </p>
      <p>
        Figure 5 presents a basic synchronization step of individual
disciplines (see Figure 5a), i.e., mechanical, electrical, and
software engineering. Note that every discipline applies
domain specific quality assurance activities [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ] with limitations
on overlapping quality assurance tasks, i.e., defect detection
across disciplines, tools, and data models. Thus, a key
challenge is bridging the gap between heterogeneous environments.
The ASB approach enables an automation supported
synchronization step, i.e., based technical integration of tools and
semantic integration of data models (see Figure 5b) [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]. Note
that frequent synchronization will lead to a more consistent
engineering data base (EDB) applicable for all related
disciplines.
(a) Synchronization across various Disciplines including comprehensive QA activities (b) Automation Service Bus
iifcceganhC tnegemCChhaannggee EMleecchtrainciaclaElEnngginineeeerriinngg QQAA ChangeSy&amp;ncChornofnliicztaRtioensolution TTToooooTolllEMeSlceeWchc..niocfaTlIoIt..rconpeheTnotelsgWrASanoCtariAkolyfDlnsoAiws
l-opeS anaMChange Software Engineering QA QA ModelMec.
o
T
      </p>
      <p>This synchronization step addresses all systems engineering
phases, typically separated by milestones and signal states.
Note that signals are the common concepts used for
synchronization, change management, and signal change handling.</p>
    </sec>
    <sec id="sec-8">
      <title>C. Object Change Management</title>
      <p>
        Change management of common concepts, i.e., signals in
hydro power plants or – more general, engineering objects in
other domains, is the most critical use case in engineering
projects. Figure 6 presents the implemented change management
workflow at our industry partner based on the common concept
of change handling (presented in Figure 3) involving electrical,
mechanical and process, and software engineers [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ].
      </p>
      <p>Changes
1</p>
      <p>Electrical Plan</p>
      <p>ToolData
Elec. Engineer</p>
      <p>Engineering
Database
Engineering</p>
      <p>Ticket
Notification
5</p>
      <p>Basically, an electrical engineering executes a change in a
defined project phase, e.g., during the basic engineering phase
(see Section II-A for an overview of observed project phases at
our industry partner). Note that the electrical engineer applies
an electrical planning tool and modifies the underlying
electrical data model, e.g., circuit diagram (1), by changing and/or
removing signals (or engineering objects). The engineering
data base (EDB) holds the current project data from previous
phases and/or check-ins conducted by engineers coming from
different disciplines. The modified signal information is passed
via a defined and tool-specific transformer (T) to the ASB (2)
and is compared with the current signal information located at
the EDB (3). Differences are presented to an engineer, typically
a systems integrator and/or project manager who are
responsible for a consistent data base. Changes can be accepted or
rejected by the systems integrator via web frontend.</p>
      <p>Removed signals (4) are specific type of changes and
require a more specific handling within an engineering project.
Assuming that an electrical engineer removes defined signals,
e.g., obsolete sensor signals, by applying the presented change
management workflow (step 1, 2, 3, and 6), the workflow will
force related tools to remove the signal in the corresponding
data models as well. For instance, the signal will be removed in
the function block diagram of the software engineer without
any warning – the signal will disappear and cannot be used for
further process steps. A more critical result of signal removal is
that a connection point might become disconnected (because of
a missing sensor) caused by the workflow rather than by the
software expert. To overcome these “unintentional surprises”
(signals will be disappear in the related data models) removed
signals will initiate an engineering ticket (5), which (a) notifies
related engineers about the signals which are going to be
removed and (b) enable the response to these actions before
checking out the modified data models. Major benefit of
applying engineering tickets is that engineers can discuss and
response to changes and removed signals early, i.e. during every
check-in process. Note that removed signals can be rejected by
the system integrator as well; an appropriate notification of the
decision must also be passed to all related engineers.</p>
      <p>The pilot application at our industry partners showed that
selective notification of engineers based on removed signal
information (and as a next step notification of all critical
changes) turned out to be most valuable for project and quality
managers to enable early discussion on selected changes and
increased product quality (early identification, prediction and
prevention of candidate defects caused by changes). Thus the
implemented change management process is a promising
starting point for applying quality assurance tasks within an
engineering project in the automation systems domain.</p>
    </sec>
    <sec id="sec-9">
      <title>D. Quality Assurance Support with Focussed Reviews</title>
      <p>
        Assuming that a hydro power-plant includes a set of up to
40.000 signals, change management and quality assurance
become challenging [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]. Manual synchronization of lists of
signals (and engineering objects) and defect detection in case of
changes are time consuming and error prone. Thus, the
automation supported synchronization process (presented in
Section IV-C) based on common concepts can reduce effort for
synchronization and increase project and product quality.
      </p>
      <p>
        In context of ASB application quality assurance in
heterogeneous engineering environment focuses on two important
aspects [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]: (a) individual and isolated quality assurance tasks
conducted by experts in their assigned disciplines (e.g.,
mechanical and process, electrical, and software engineering) and
supported by isolated tool solutions; (b) quality assurance on
overlapping areas, i.e., common concepts, where different
disciplines have to collaborate and synchronize data. Figure 8
presents the focus of quality assurance (also introduced in
Figure 5) by example.
      </p>
      <p>Mechanical &amp; process
properties „process“</p>
      <p>QA
InPstirpuem&amp;entation</p>
      <p>
        Highlighting the differences during signal check-in (see
Figure 7 for an example) and selective notification of affected
engineers by applying engineering tickets (see Figure 6 for the
basic workflow) will enable focused discussions and
problemsolving activities of engineers affected by the change and/or
defect. Instead of discussing 40.000 signals (including an
additional process step for identifying changes) the presentation of
signal changes enables focusing discussions on real deviations.
Note that expert estimations of our industry partners assume
that typical projects include approximately 20% of signal
changes along the project course. Focusing on real changes and
defects will significantly reduce synchronization and defect
detection effort and will increase project and product quality.
Highlighted changes and the presentation of changes will
reduce the number of signal comparisons and signal checks
significantly and – as a consequence – will decrease effort and
cost. With respect to quality assurance, reviewers and
inspectors [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] can focus directly on the changes to identify defects
and deviations.
      </p>
      <p>
        Lessons learned from business IT software development
and software inspection [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] as a well-established static quality
assurance technique in software engineering [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ][
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] might lead
to software inspection and reading technique [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] and reading
technique variants [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ] with focus on automation systems
development projects in heterogeneous engineering
environments. In addition, next steps can also include the analysis of
engineering objects/signals and the impact of changes with
respect to other related components which are not directly
changed by an individual engineer, e.g., the impact on
components which might have been affected by the change (but were
not covered by the change request so far).
      </p>
    </sec>
    <sec id="sec-10">
      <title>E. Integration Testing in Heterogeneous Environments</title>
      <p>
        Software testing is well-known in common software
engineering practice to identify defects based on executable
software code [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] systematically. Based on software testing
bestpractices, several test levels apply, e.g., unit test, integration
tests, and system and acceptance tests [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. For instance
integration tests from business IT Software development focus on
testing the interfaces, integrated components and the data
exchange between components. Concerning automation systems
engineering projects, similar test levels are applicable [
        <xref ref-type="bibr" rid="ref24">24</xref>
        ].
Thus, we see the concept of integration testing (learned from
business IT software development) as “comparable” to
heterogeneous automation systems development, where different
disciplines should be integrated and tested.
      </p>
      <p>
        For instance, a hardware sensor is connected to a systems
interface (e.g., a switchboard) and connected to a software
interface (e.g., control application or visualization software)
representing the software behavior [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ][
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]. Considering individual
disciplines as components (and individually) tested via “unit
tests” within the related isolated discipline, linking and testing
these individual component and disciplines on architecture
level might refer to integration tests including assigned and
tested components and interfaces. Similar to integration tests in
software engineering, integration tests in automation systems
engineering projects will find different defects on architecture
level which could hardly be identified by inspection and/or
isolated QA activities within one discipline. Examples of
candidate defects in the automation systems domain are presented
in Figure 9:

      </p>
      <p>D1: Missing link between sensor (Sx) and system interface
(I2). No value will be available at the software control
application.




Sensor</p>
      <p>D2: Correctly wired sensor (S2) to the system interface I3
but no link to a software variable, i.e., sensor value will
not be analyzed and used for further applications.</p>
      <p>D3: Multiple connected sensors (S2 and S4) to I5 and V3.
D4: Correctly wired sensor S5 to system interface I6 and
wired connection at I6. Nevertheless the connection got
lost on the way to the software variable, e.g., caused by a
cable break.</p>
      <p>D5: Software Variable V5 not linked to system interface
(Ix) and sensor (Sx).</p>
      <p>
        Figure 9 shows related stakeholders/disciplines and
interfaces [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] and illustrate highlighted defects across disciplines
which cannot be identified easy during check-in processes
and/or individual and local quality assurance activities.
      </p>
      <p>D1
D2
D3
D4</p>
      <p>System
Interface</p>
      <p>I1
I2
I3
I4
I5
I6
?</p>
      <p>Software Software
Interface „Behavior“</p>
      <p>D5</p>
      <p>V1
V2
V3
V4
V5
Wiring</p>
      <p>Configuration</p>
      <p>Use of Data</p>
      <p>
        Integration testing in automation systems development is
typically embedded within the commissioning phase, where
individual disciplines are linked to each other manually.
Inspection and testing are applied stepwise during this ramp-up
phase. Defects have to be located manually by consulting
individual plans from heterogeneous sources. This manual activity,
conducted by integration engineers and experts is
timeconsuming and require high effort and cost (e.g., tracing
individual signals across the plant manually). The ASB approach
enables engineer in testing plans from different sources based
on the common concepts. This so-called “End-to-End” test
enables engineers in testing the overall chain of signals across
heterogeneous environment from hardware sensors to software
variables [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. In addition efficient navigation features have
been implemented (a) to navigate to signals in various plans to
see the implementation of the functional requirements (without
consulting the paper work) and (b) to link runtime data during
the commission phase within the affected engineering plan
(e.g., presentation of runtime and/or simulation within a PDF
document)2. Automation-supported integration testing of
engineering plans from various sources and efficient navigation
between affected plans can improve systems development
processes and the commissioning phase significantly.
      </p>
    </sec>
    <sec id="sec-11">
      <title>2 See http://cdl.ifs.tuwien.ac.at/en/node/29 for a detailed de</title>
      <p>scription of these use cases and screen casts.</p>
    </sec>
    <sec id="sec-12">
      <title>F. Project Observation and Control</title>
      <p>
        Observing and controlling engineering projects are key
activities of project and quality managers. Project observation in
homogenous environments, e.g., business IT software projects,
is supported by individual methods and tools. Software
cockpits have been established as project control centers aiming at
summarizing and presenting most relevant project information
for project and quality managers, e.g., schedule, budget, project
progress, and quality [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ][
        <xref ref-type="bibr" rid="ref16">16</xref>
        ]. Note that the collection and
analysis of project related data is typically limited to
homogeneous engineering environments like in software engineering
projects. Additional challenges arise in heterogeneous
environments, e.g., in automation systems development projects,
when linking data models and data from various sources.
      </p>
      <p>Based on discussions with managers at our industry partner,
the key challenge is to measure the impact of changes within
an engineering project, i.e., identifying the number of changes
per time interval and/or per project phase. Today expert
estimations regarding the number of changes along the project course
are the foundation for capturing change management metrics
(e.g., 20%) because no detailed data regarding the real number
of changes per project exists.</p>
      <p>The ASB approach enables a more detailed view on
changes by providing real data according to change management
processes along the automation systems development process
(see Section II-A for a detailed description of a common
engineering process and Section IV-C for a change management
process). Common concepts (see Section IV-A) enable
efficient data exchange between various tools and data sources and
are the foundation for process observation and control. Note
that common concepts (i.e., signals) are used to observe and
analyze the process across disciplines and tool borders and to
control the next steps of the engineering process. Based on
common concepts frequent synchronization between different
disciplines becomes possible (see Section IV-B) and enable
process analysis based on real and captured data.</p>
      <p>The analysis and presentation of change management data
enable a more detailed view on the engineering process within
an engineering cockpit. Figure 10 presents a snapshot of the
implemented engineering cockpit, a “window to engineering
data”, based on captured signal change management data from
a real engineering project. The engineering cockpit from the
perspective of managers (Figure 10a) enables an overview on
the project state (visualized by the project progress)
summarizing various groups of engineering objects (e.g., components)
over time. Note that the visualization includes the current state
of engineering objects (i.e., signals) per project months and the
number of expected engineering objects of the completed
automation system. Thus, the project progress becomes traceable
and observable. A “drill-down” feature enables a more detailed
view on an individual component to see subcomponents on
various levels of detail.</p>
      <p>Figure 10b illustrates the volatility of engineering objects
(i.e., signals) e.g., the number of new, removed and modified
signals per project months. This metric enables project
assessments and evaluations of the engineering objects within a
project. A high number of changes (modified and removed
signals) might indicate improvement options of the engineering
process because some components might have been reused
during system development (including some required changes).
Nevertheless, a more details investigation of project
managements will be necessary to fully understand the signal change
results; the engineering cockpit provides a visualization of the
captured data and metrics. The initiator of the change, i.e., a
tool or engineer, might be an indicator for improving individual
disciplines and the application of components. Thus, the
engineering cockpit provides a view on the tool impact of changes
(Figure 10c).</p>
      <p>(b) Volatility of Engineering Objects
(a) Engineering Cockpit Overview with „Drill-Down“
(c) Tool Impact of Changes</p>
      <p>Development projects of large scale automation systems,
e.g., manufacturing plants, steel mills, and power plants,
typically include a large and heterogeneous group of stakeholders
who participate in systems engineering projects. These
stakeholders come from different disciplines, e.g., mechanical and
process engineering, electrical engineering, and software
engineering, using different tools (technical heterogeneity) and data
models from various sources (semantic heterogeneity).
Nevertheless, heterogeneous tools and data models hinder (a)
efficient collaboration between disciplines, (b) effective and
efficient quality assurance activities across disciplines and domain
borders, and (c) make a comprehensive project and process
observation and control more difficult. The Automation
Service Bus (ASB) provides a middleware platform that aims at
bridging the technical and semantic gap between tools and data
models from various disciplines.</p>
      <p>
        Based on previous publications (e.g., [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]) this paper
summarized the basic concepts of the ASB approach and illustrates
a prototype application at an industry partner to improve
collaboration, quality assurance, and project observation and
control in a real world application context.
      </p>
      <p>
        RQ1: How can we enable data exchange between
heterogeneous data sources? Efficient data exchange approaches between
data models from heterogeneous sources are the foundation for
(a) efficient quality assurance activities and (b) a
comprehensive process observation capabilities across tools and domain
borders. To overcome semantic heterogeneity we introduced
the virtual common data model (VCDM) that bridges the gap
between different sources [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ][
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. Based on various tool data
models (from various sources) the VCDM holds the common
concepts, e.g., signals, used for collaboration and data
exchange based on an agreed subset of data elements.
RQ2: How can we enable efficient quality assurance across
disciplines? Common concepts represent overlapping
information areas (see Figure 8) where engineers have to
collaborate and exchange data. Furthermore, these common concepts
are used for synchronizing disciplines along the engineering
process. Note that frequent synchronization supports change
management and defect detection. In common industry practice
every discipline applies individual quality assurance activities.
In addition, the ASB enables two novel quality assurance
approaches for defect detection: focused inspection and
end-toend integration testing. Focused inspection enables the
identification of defined defects in the overlapping information areas
where two or more disciplines collaborate by applying
common concepts. The end-to-end test enables semi-automated
testing of the signal chain from hardware sensors to software
variables.
      </p>
      <p>
        RQ3: How can we enable a comprehensive view on the
engineering project? Based on the VCDM process observations we
introduced an Engineering Cockpit [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ], aiming at (a)
providing stakeholder related data derived from the engineering
project databases and (b) enabling control of project steps based
on the analysis results [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]. In addition to process related
information and metrics, project context information and quality
data might be useful to support project and quality managers in
better assessing and controlling the automation systems project.
Lessons Learned &amp; Future Work. Based on discussion with
our industry partners and our experiences in developing
business IT software products, we see the technical integration
of tools and semantic integration of data models as very
promising approaches to support different types of projects,
where different stakeholders and disciplines are involved,
and/or heterogeneous engineering environments can be
observed.
      </p>
      <p>Future work of this ongoing research project will focus on
(a) different aspects of common concepts (in other engineering
domains), (b) automation supported process modeling,
observation, and validation, and (c) enhanced and
automationsupported quality assurance methods.</p>
      <sec id="sec-12-1">
        <title>ACKNOWLEDGMENT</title>
        <p>This work has been supported by the Christian Doppler
Forschungsgesellschaft and the BMWFJ, Austria. We also
want to thank the domain experts at our industry partners for
their valuable insight into engineering projects and their
feedback on the prototypes presented in this paper.</p>
      </sec>
    </sec>
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