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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>New complex product introduction by means of product configuration</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Martin Bonev</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Manuel Korell</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Lars Hvam</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Technical University of Denmark</institution>
          ,
          <country country="DK">Denmark</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2013</year>
      </pub-date>
      <fpage>29</fpage>
      <lpage>30</lpage>
      <abstract>
        <p>Configuration systems have widely been applied to efficiently address the customization responsiveness squeeze of companies dealing with Mass Customization. Over time, several frameworks have been introduced to enable their systematic planning, analyses, development and implementation. Traditional research has thereby either focused on defining modelling techniques for the configuration model of stable products, on improved configuration algorithms, or on the impact of configurators on companies' operations. However, little attention has yet been paid how the growing need for product innovation can effectively been supported. Especially for engineering companies moving towards Mass Customization, compared to mass producers the challenges caused by the complexity of their products and by the highly uncertain markets are much higher. This study develops and validates a framework which enables the use of configuration systems along the introduction of complex products. It in particular examines (1) what are suitable development strategies for configuration systems during product innovation, (2) how product development and configuration development can be aligned and managed, and (3) how supplier integration can be achieved.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1.1 Background</title>
      <p>With mass customization (MC) companies are aiming at
effectively addressing the customization-responsiveness
squeeze, i.e. the necessity of offering custom tailored
products at nearly mass production efficiency [Tseng et al.,
2001]. Since its introduction in the late 1980’s [Davis,
1989], the concept has received much attention from both
practitioners and scientists. General strategies and advanced
IT systems, such as configuration systems (CSs), have
potentially helped companies to effectively cope with global
competition and increased customer demands [Salvador et
al., 2009].</p>
    </sec>
    <sec id="sec-2">
      <title>1.2 Motivation and outline of the paper</title>
      <p>While much of the research has yet focused on developing
models and theoretical frameworks, little empirical studies
have explained the effective introduction of new customized
products [Slamanig et al., 2011]. Notably the use of
configuration systems has seldom been discussed in the context of
radical innovation processes [Hara et al., 2012]. Thus
considering the challenges of dynamically changing markets
and increasing product complexity [Blecker et al., 2006],
further guidance based on empirical evidence is needed.
Especially for engineer-to-order (ETO) manufacturers who
are moving from an individual customization to a partly MC
these challenges are particularly important. Compared to
mass producers, their products are typically more complex
and high uncertainties of demands make planning activities
more difficult [Rahim et al., 2003].</p>
      <p>The emphasis of this study is therefore to investigate how
new products can be launched effectively in situations in
which product complexity (internal complexity) is rather
high and where only little information about the customer
requirements (external complexity) exists. A particular
attention is thereby paid on how CSs can support product
innovations for significant product renewals.</p>
      <p>Based on a literature study (Section 2), the paper first
examines existing approaches for MC with regard to the use
of CSs in the context of new product introduction. Relevant
frameworks are adapted to better meet the requirements of
ETO manufacturers pursuing MC strategies and product
innovation with product configuration (Section 3-4). Next,
the newly introduced framework is applied on an industrial
case study (Section 5), where a configuration model was
initially developed. The achieved findings and practical
implications are eventually discussed (Section 6).
2</p>
    </sec>
    <sec id="sec-3">
      <title>Literature Review</title>
    </sec>
    <sec id="sec-4">
      <title>2.1 Product configuration and mass customization</title>
      <p>Offering bespoke products to customers affects the entire
product realization process starting from the order
acquisition to the order fulfilment [Forza and Salvador, 2002].
According to Jiao and Tseng (2004) the impact of
customization can be described with the generic domains of an
organization [Jiao and Tseng, 2004], where to begin with
customer satisfaction can be achieved through the efficient
match of the requirements to the offered solution space of
product variants. Salvador et al. (2009) refer to this process
as assortment matching, in which suitable software helps to
link the existing solution space to customer’s needs
[Salvador et al., 2009]. The most common software systems that
enable the realization of an efficient assortment matching
are configuration systems [Forza and Salvador, 2002].
Being a subtype of a knowledge-based expert systems, CSs
formally represent the product knowledge relevant to the
customer (product features), allowing a complete definition
of possible product outcomes (customized functional
features) with a minimum of entities [Hvam et al., 2011].</p>
      <p>More recently, researches have investigated the use of
CSs not only as sales tools, but also in support of the entire
specification process, i.e. the order acquisition and order
fulfilment process [Forza and Salvador, 2002]. Helo et al.
(2010) for instance propose a business model for the use of
configuration systems throughout the entire specification
process of a product [Helo et al., 2010]. The authors discuss
how sales configuration can first be used to translate
customer needs into functional requirements of a product. In
the physical domain, product configuration then matches the
chosen set of functionalities into design parameters. Even
though not implemented in the study, process configuration
can eventually be used to select on a high level suitable
production and logistic steps for the subsequent processes.
Figure 1 below illustrates a generic value chain of a
manufacturing company including its specification process.
Depending on the scope of the project, CSs can potentially be
implemented to support wholly or only partly the
specification process [Hvam et al., 2008].</p>
      <p>Customer</p>
      <p>Sales</p>
      <p>Specification process
Product
design</p>
      <p>Manufacturing
engineering
Purchasing</p>
      <p>Planning</p>
      <p>Production</p>
    </sec>
    <sec id="sec-5">
      <title>2.2 Recent trends in product innovation</title>
      <p>Obviously, by integrating the different customization
domains into the configuration process helps to provide
salesmen with more accurate estimations of time and cost of
existing products. However, over time competition forces
firms to update their established product portfolio. Smith et
al. (2012) discuss two major reasons for companies to
regularly work on product innovation:
1. customers change requirements, and
2. product performance needs to be constantly
improved [Smith et al., 2012].</p>
      <p>Hence, in the first case new products are only introduced
when considerable large discrepancy exists between
customer needs and the provided functionality of existing
prodCalculation
Delivery/
assembly
ucts. In the latter case new ideas and technologies keep
customers engaged with the products and thus stimulate
sales [Howard et al., 2011].</p>
      <p>In majority of the cases, working on product innovation is
typically based on existing products, where often more than
70% of the development tasks are related to redesigning,
improving, and extending the products offered to the market
[Ullman, 1997]. To achieve high productivity in the
innovation, companies are on the one hand pressured to employ
adequate tools and methods that allow an in-depth
understanding and managing of knowledge related to products,
processes, as well as to their project environment [Vezzetti
et al., 2011]. On the other hand, to compete on dynamically
changing markets, it has become essential to transform the
innovation process from a linear to a spiral model with short
and direct iterative loops and feedback cycles [Cooper and
Edgett, 2008]. By doing so, initial ideas and prototypes are
immediately tested, where early feedback is used for further
development [Salvador et al., 2009].</p>
      <p>As technology is progressing and being used in more and
more areas of business, recent studies demonstrate that a
high level of technical assessment in innovation
significantly improves companies’ business performance. With the use
of advanced technologies, probable solutions, risks and
potentials can initially be evaluated. Moreover, when
considering the costs and benefits from suitable technology in
early stages of the innovation process, the need for
technology alliances can upfront be detected [Cooper and Edgett,
2008].</p>
    </sec>
    <sec id="sec-6">
      <title>2.3 Product configuration, innovation and vendor collaboration</title>
      <p>Despite configuration systems are playing an essential part
in the customization process of manufacturers, in academia
their use has typically been limited to streamline
specification processes of matured and well established products,
usually offered by one vendor [Blecker et al., 2006; Hvam
et al., 2008; Forza and Salvador, 2008]. Forza and Salvador
(2002) for example discuss the use of a configuration
system in support of the order acquisition and fulfillment
process of products from one vendor with high but relatively
simple product variety [Forza and Salvador, 2002]. Hvam et
al. (2006) argue for the use of configuration systems as a
way to improve the quotation process of ETO products or
even systems. By calculating budget quotations, the
configuration system manages to create sufficiently precise price
estimations offered by one company [Hvam et al., 2006].
Also Haug et al. (2012) investigate the use of CSs in several
manufacturers of rather complex and engineering intensive
products. The authors illustrate the employment of different
CS development strategies in support of specifying the
existing product portfolios [Haug et al., 2012].</p>
      <p>Wang et al. (2009) introduce a framework for assessing
configuration changes of exiting products. Based on the
operational performance of suppliers, a generic algorithm is
used to calculate how a changed part affects the preference
for individual suppliers. The framework is exemplary tested
on a simple electronic device. Even though the authors
include the collaboration of several vendors into their
framework, stable products with only minor product changes
(different product variants) for relatively simple products
have been examined [Wang et al., 2006]. Ardissono et al.
(2003) propose a theoretical framework for the use of a
web-based configuration system which strives to enable the
collaboration between different vendors. The authors
however omit to explain how the CSs should be used in praxis,
especially with regard to complex products and radical
innovation [Ardissono et al., 2003].
3</p>
    </sec>
    <sec id="sec-7">
      <title>Research Design and Objectives</title>
      <p>From reviewing the literature it can be stated that none of
the mentioned case studies considers how CSs can be used
in the cause of innovation and evolvement of a complex
product family, in particular not together with the
coordination between different suppliers or vendors. At the same
time, prevailing on increasingly competitive markets
requires efficient innovation processes which are flexible
enough to quickly adapt to a fast changing environment
[Cooper and Edgett, 2008]. This study therefore aims at
developing a framework which addresses the dilemma of
being innovative on dynamically changing markets and yet
still efficiently providing custom tailored products. In order
achieve practical validity, a case study with a company is
performed. The collaboration is organized through action
research where the researchers were actively involved in a
transformation process [Coughlan and Coghlan, 2004]. The
industrial partner is a start-up company, a contractor with a
strategic collaboration with several ETO companies.</p>
      <p>Already at an early stage of its establishment, the
company has realized the potential of using advanced IT
technologies and a well thought marketing approach to gain a
competitive advantage within its industry. The alliance with the
strategic partners enabled sharing the otherwise
unreasonable IT investment and the related financial risks. At the
same time, such a strong collaboration facilitated the
exchange of knowledge concerning the products and potential
market segments. Rigor of data was insured through
foregoing interviews and through a series of short action research
cycles conducted in the cause of twelve months.
4</p>
    </sec>
    <sec id="sec-8">
      <title>A Procedure for Implementing Complex</title>
    </sec>
    <sec id="sec-9">
      <title>Product Configuration in NPD</title>
      <p>Several frameworks for the development and
implementation of CSs exist in literature. For the study at hand, a
widely used and well-structured seven phase procedure
introduced by Hvam et al. (2008) was chosen. The procedure is
based on the object oriented project life cycle (analysis,
design, implementation and maintenance), and further
contains methods for analyzing product ranges as well as the
related business processes [Hvam et al., 2008]. Rather than
describing each of the phases in detail, in the following, we
focus our attention only on the aspects that are critical with
respect to innovation and new product development (NPD).</p>
    </sec>
    <sec id="sec-10">
      <title>4.1 Clarifying the innovation strategy</title>
      <p>By implementing CS several benefits can clearly be gained
[Bonev and Hvam, 2012]. Yet, when planning and
performing configuration projects with complex products and
multiple users, the desired results are often not being achieved.
According to Haug et al. (2012) a major challenge for the
success of a configuration project is that for complex
products, the configuration task is difficult to be estimated. In
result projects often become significantly more costly than
anticipated or companies fail to create prototypes that
indicate the potential benefits. Another reason for abandoning
initiated configuration projects is that by implementing a CS
a substantial part of the business processes have to be
redesigned. In case the required organizational changes are not
widely accepted by the employees, the system will most
likely not be used [Haug et al., 2012]. To overcome these
challenges it is important to establish a clear innovation
strategy that promotes configuration projects which are
likely to succeed and where the risk for failure is kept to a
minimum. Thus, to be able to make reasonable decisions
about the right innovation strategy it is inevitable to make
use of relevant performance metrics. A way of assessing the
performance of NPD is through monitoring the NPD
productivity measured as the output from the NPD process
divided by the input [Coorper and Edgett, 2009]:


=

( 
 &amp; 
)</p>
      <p>As indicated in Figure 2 below, in today’s quick changing
business environment the outcome of the NPD can be rather
uncertain. Estimations about long term sales development of
new products remain vague and can cause high risks with
regard to their success on the market [Oriani and Sobrero,
2008].
In order to increase the NPD productivity and reduce risk
of failure in the more reliable planning horizon, i.e. at an
early stage of the innovation process, early R&amp;D spending
should be kept low. For ETO firms moving towards MC this
can be achieved in two major ways. First, it is beneficial to
establish strategic alliances with reliable suppliers. By
sharing and coordinating innovation activities for complex
products and knowledge about customer preferences and
trends, individual investments and risks concerning the
success on the market can be reduced [Pullen et al., 2012].
Secondly, for configuration projects the R&amp;D spending is
mainly driven by the development of the configuration
model and by the related IT investment. At an early stage of
the configuration project it is therefore important to be clear
about what are the essential (“need-to-have”) functionalities
the CS needs to have and which of the possible
functionalities can be categorized as “nice-to-have”. As the product is
maturing over time and turnover from sales is increasing,
further investment towards the less prioritized
functionalities can be taken and the use of the CS can gradually be
extended. From a financial perspective a strategic alliance
and a stepwise configuration development stimulates an
early return on investment (ROI) and increases the
probability for more successful new product launches. Furthermore,
a stepwise CS implementation encourages employees to
embrace the organizational changes caused by the system,
while its functionalities are being extended over time.
In sum, by involving the strategic partners in the
configuration project, investment and risks can be shared and a wider
range of the specification activities can be considered.
Having set the requirements for the innovation strategy, in the
following steps the some essential characteristics of the
project life cycle will be discussed.</p>
    </sec>
    <sec id="sec-11">
      <title>4.2 Developing the specification process</title>
      <p>Before starting with a detailed analysis on the planned
product innovation, if it hasn’t been done yet, it is first useful to
establish an overview over the current specification process
at hand. From a supply chain perspective it is important to
understand how the communication between various
stakeholders is organized and to what extend they are influenced
by the specification process. A typical sales and delivery
process of ETO firms is illustrated in Figure 3 [Brunoe and
Nielsen, 2012]. In contrast to mass producers, at the point of
sales ETO firms usually have only a limited amount of
information specifying the product and a significant amount
of it has yet to be designed [Rahim and Baksh, 2003]. At the
same time ETO firms still need to be able to create legally
binding sales quotes which define the product to a
considerable level of detail, ensuring that the communicated price
and lead time results in a satisfying profit. Since generating
quotations is no guarantee for receiving an order [Kingsman
and De Souza, 1997], the sales process has to be effective
and very cost efficient. For companies delivering ETO
products the main purpose of having a CS is therefore to
automate the sales and ordering process [Haug et al., 2009].
In result, this initial analysis of the involved specification
activities helps to assess the requirements for the subsequent
automation.</p>
      <p>Next, a TO-BE specification process supported by a CS
can be defined. Scenario 2 in Figure 3 illustrates the most
widespread approach for CS [Salvador et al., 2009], namely
a sales configurator. In other less common situations, ETO
companies might have more benefits from the
implementation of a solely technical CS (Scenario 2). In such a case the
system would function as a design automation system for
generating technical specifications for production. Due to
the involvement of complex calculations, a major challenge
is thereby to cover the entire technical specification [Elgh,
2008]. Next, the simultaneous implementation of both, a
sales and a technical configurator is repressed by the
remaining two scenarios. While in Scenario 3 two separate
systems would cover the two aspects, Scenario 4 represents
an integrated solution for the configuration. However, as the
integration to other IT systems and to advanced calculation
and CAD applications, such as to Mathcad and Inventor, is a
major cost driver, in the first step this investment it is often
unfeasible.</p>
      <p>Consequently, even though the use of advanced CS can
potentially sustain the entire specification process (Scenario
4), to keep the investment costs and the organizational
changes at a low level, in the first step (Step 1) of
implementation, only the needed process steps are to be assisted
by the system. In the subsequent steps (Step 2 etc.), more
and more activities related to the specification of a product
can be automated. In the majority of the cases it is feasible
to start with the development of a sales CS, as for example
investigated by Salvador et al. (2009). Such a system could
then be used as a marketing tool, where in the introduction
and growth phase of the product life cycle the focus is on
creating customer awareness of the product and on trial of
different product variants [Kotler et al., 2012]. With the
right analytical capabilities [Davenport and Harris, 2007],
companies could quickly uncover customer preferences and
thus further extend their product portfolio towards the
required product features.</p>
    </sec>
    <sec id="sec-12">
      <title>4.3 Aligning product analysis and development with configuration development</title>
      <p>Since in most cases product innovation builds upon existing
products [Smith et al., 2012], after clarifying the
implementation steps, an analysis of the most similar product
architecture needs to be taken. Ulrich (1995) defines product
architecture as: (1) the arrangement of functional elements; (2)
the mapping from functional elements to physical
components; and (3) the specifications of the interfaces among
interacting physical components. For the analysis of the
architecture, often the Quality Function Deployment (QFD)
and the Design Structure Matrix (DSM) have widely been
utilized. With their help customers’ needs are identified and
linked into the created product structure [Vezzetti et al.,
2011]. The employment of the Modular Function
Deployment (MFD) then enables the creation on decoupled
functional units, i.e. modules [Ericsson and Erixon, 1999].</p>
      <sec id="sec-12-1">
        <title>Product Model</title>
      </sec>
      <sec id="sec-12-2">
        <title>Configuration Model</title>
      </sec>
      <sec id="sec-12-3">
        <title>Supplier x-xy</title>
      </sec>
      <sec id="sec-12-4">
        <title>Decoupled modules</title>
      </sec>
      <sec id="sec-12-5">
        <title>Standardized interfaces</title>
      </sec>
      <sec id="sec-12-6">
        <title>Platforms</title>
      </sec>
      <sec id="sec-12-7">
        <title>Supplier z</title>
        <p>Another way of representing the product architecture is
through the hierarchy structure of the Product Variant
Master (PVM) technique. By following the basic principles of
object oriented modelling, such as generalization,
aggregation and association, the PVM technique uses the Unified
Modeling Language (UML) standard [Hvam et al., 2008].
Regardless the chosen modeling technique, with product
platforms in the development process are more stable
product architecture can be achieved [Meyer and Lehnerd,
1997]. To ensure the collaboration between suppliers of a
complex product, the individual components should be
integrated as separate modules with decoupled
functionalities and with clear interfaces to the related product
components. Figure 4 illustrates the integration of components
coming from different vendors into the entire product
model. While some of the modules may be delivered from
different suppliers (indicated by “x-xy” in the figure), for other
modules only one supplier (“Supplier z”) may exist.</p>
        <p>A product model generally aims at representing the
physical components and their functionalities. From an object
oriented perspective, the development of a configuration
model however characterizes the logical combination of
classes and their attributes. Each class may represent
physical components or other important product characteristics.
Such characteristics could e.g. describe geographical,
geometrical and functional product aspects, such as the targeted
market or the shape and style of a product. Depending on
the modelling environment of the CS, as indicated in Figure
4 the configuration model can then be illustrated as a PVM.</p>
        <p>
          Even though the composition of the configuration model
might be slightly different from the one of the product
model, the same structural concerns are relevant for its
knowledge base. Thus, since a growing product complexity
typically leads to an increasing configuration complexity,
wherever possible the configuration structure should consist
of separate configuration modules (classes) with
encapsulated constraints [
          <xref ref-type="bibr" rid="ref32">Tiihonen et al., 1996</xref>
          ]. To simplify the
model, also here standard interfaces among modules with a
minimum number of cross related constraints are beneficial.
Classes which can be carried over across product families
are then to be grouped to platforms.
        </p>
        <p>Furthermore, in cases where the final product components
are unclear yet, a Concurrent Engineering like approach can
be achieved by the use of a “black-box” configuration
[Whitney, 1988]. In this case configuration classes which
contain dummy attributes and constrains for the presumed
product functionalities can be established in parallel to the
development of the physical product components. Once the
final components and the corresponding supplier
specifications are available, the placeholders created in the CS can be
fed with the actual information. Finally, by using the spiral
model [Cooper and Edgett, 2008; Hvam et al., 2008], a
quick trial and error testing of the CS helps to detect critical
configuration aspects and product components for which the
product information is yet fragmented or not available.</p>
      </sec>
    </sec>
    <sec id="sec-13">
      <title>5 Applying the Framework</title>
      <p>The described framework for using CSs in the process of
NPD of complex ETO products was tested for validation on
an industrial case study. The thereby gained results will in
the following be briefly discussed.</p>
    </sec>
    <sec id="sec-14">
      <title>5.1 Developing the TO-BE specification process at the case company</title>
      <p>Having established and overview of the AS-IS specification
process, a TO-BE specification process for a stepwise CS
implementation was created. The main requirements for
Step 1 were:
1. The specification errors, long lead times and
limited product representation should be improved by
the use of a sales configurator.
2. The sales configurator should:
a. Contain only product features which are</p>
      <p>essential for the customer.
b. Store not essential product features as
predefined default values and represent
for the majority of the cases a
welldesigned product [Mandl et al. 2011].
c. Be available locally on salesmen’s
com</p>
      <p>puters.
d. Provide a sufficiently accurate (95%)</p>
      <p>price and lead (delivery) time estimation.
e. Provide a 3D graphical user interface
(GUI) of the product, where a direct
impact of the configured commercial
features on time and cost is to be seen.
f. Generate a quotation for the customer
including a description of the configured
product.
g. Save the customer’s information and the
configuration status for a later
reconfiguration.</p>
      <p>h. Enable the selection of non-standard
choices for better adaptation of the offered
solution space.</p>
      <p>The remaining specification process should be
divided into a configurable technical specification
process and into a non-configurable engineering
and procurement process.</p>
      <p>The configurable technical specification process
should be supported by a technical product
configurator, the remaining specifications should be
created in a traditional manner (through CAD and
advanced calculation systems).</p>
      <p>Both, the sales and the technical CS should be
based on the same configuration model.</p>
      <p>The output of each of the SCs should work as input
for the other SC.</p>
      <p>The (technical) product configurator should:
a. Contain all design specifications of the
product which can be configured within
the CS.
b. Be available on the intranet
c. Estimate price and lead times (production,
delivery, commissioning) as accurate as
possible (ca. 99%).
d. Contain only basic descriptions and static</p>
      <p>pictures of the product.
e. Generate technical specifications and</p>
      <p>manuals for the involved suppliers.
f. Save the configuration status for a later</p>
      <p>reconfiguration.</p>
      <sec id="sec-14-1">
        <title>Sales Configuration</title>
      </sec>
      <sec id="sec-14-2">
        <title>Product Configuration Quotation &amp; Sales Commercial</title>
        <p>Figure 5 shows a high level representation for the chosen
initial CS implementation (Step 1). To meet the
requirements, a variation of Scenario 3 was selected. For the later
steps of implementation (Step 2 etc.), the sales configurator
should be available on the internet, where a wider range of
customer awareness can be achieved. Another aspect e.g.
concerns the functionalities of the technical CS. In later
stages the system could have a direct integration to various</p>
      </sec>
      <sec id="sec-14-3">
        <title>Attributes Constraints</title>
        <p>60%</p>
        <p>s
50% i
n
o
t
a
40% le
r
s
s
30% ro
c
f
20% t
o
n
e
10% c
o
r</p>
        <p>P
0%
CAD and calculation software, so that a higher percentage
of the whole product specification can be created. However,
since the product consists of components from a number of
different suppliers, currently a complete definition of these
3rd party components appears to be unrealistic.</p>
      </sec>
    </sec>
    <sec id="sec-15">
      <title>5.2 Developing the configuration model at the case company</title>
      <p>A generic product model for yet to be developed product
family was created by means of the above described
modelling techniques. The corresponding configuration model was
done directly in the chosen configuration software. Since
both, the product and the configuration model were
extended over time, the solution space of the models increased
dramatically.</p>
      <p>3000
2500</p>
      <p>Figure 6 displays how the number of attributes and
constrains of the configuration model grew as it was further
completed. The growing complexity of the configuration
model led to a higher computation time and to less control
over the behaviour and the cause-effect relationships of the
system. Hence, several initiatives were taken to reduce the
structural complexity of the model. Two of them will in the
following be discussed.</p>
      <p>% of cross-relations in constraints and classes</p>
      <p>Constraints</p>
      <p>Measuring point
Figure 7: Reduction of cross-relations within the configuration
model</p>
      <p>To simplify the product structure, first the yet rather
integrated construction of the model was redesigned to a more
modular form. As described in the framework, wherever
possible, it was tried utilize modularization, i.e. to make use
of encapsulated classes and thus to reduce the number of
cross relations. Figure 7 shows how despite a further
extension of the model, a decrease from 55% to 30%
crossrelations in the model considerably reduced the number of
needed constraints. Moreover, having encapsulated classes
with little cross-relations provided a better overview over
the entire configuration model and facilitated the inevitable
debugging. In cases of unexpected behaviour, computation
or even system errors, the responsible classes could easier
be detected.</p>
      <p>Solution Space of 4 related attributes for Component A and B</p>
      <p>Category Solution Space (No. of Combinations) Structural Complexity
Technically possible 19,360,000,000,000 100%
fSaimctpolrif1ie0d each attribute by 1,936,000,000 0.01%
fSaimctpolrif1ie0d0 e(taoclheraatntcriebulimteitb)y 193,600 0.000001%</p>
      <p>Another way to reduce the complexity of the
configuration structure was to minimize ranges of attributes. Since
not every technically possible attribute value is required by
the customer, the characteristics of each attribute could be
reduced to the tolerance limit. Table 8 exemplary depicts
how a simplification of 4 attributes exponentially reduces
the solution space and hence the structural complexity of the
knowledge base. Instead of using the technical possible
solution, by limiting the ranges with factor 100 the solution
space could be reduced by factor 10^8.
6</p>
    </sec>
    <sec id="sec-16">
      <title>Conclusion</title>
      <p>
        When following MC principles, manufacturing companies
have to consider a number of characteristics. The internal
and external complexity is thereby seen as a major challenge
to be handled
        <xref ref-type="bibr" rid="ref2 ref20">(Blecker et al., 2006)</xref>
        . Especially for ETO
companies the movement towards MC seems to be much
more complex compared to mass producers
        <xref ref-type="bibr" rid="ref16 ref37">(Haug et al.,
2009)</xref>
        . Their products typically comprise a low degree of
standardization with no or little commonality, their
processes are seldom automated and they have little control over
their customer portfolio. Our study shows that in order to
better cope with arising challenges, ETO firms need to pay a
particular attention on the planning phase of a new product
introduction and the related product configuration
development. Besides the foregoing product and process analysis
        <xref ref-type="bibr" rid="ref21">(Hvam et al., 2008)</xref>
        , several additional aspects need to be
considered:
1. ETO companies using product configuration
should collaborate on innovation to reduce risk and
investment and to become more efficient with the
new product launches.
2. Configuration systems should be planned and
implemented in steps by using the spiral model,
starting only from the most important “need-to-have”
functionalities first.
3. Configuration systems should consider the product
lifecycle objectives of products, focussing first on
the creation of awareness and trial of product
variants.
4. Efficiency can be gained in later steps of
implementation, as functionalities are being extended,
and automation and further integration to other IT
systems is realized.
5. The product structure of new products needs to be
redesigned in order to be configurable, while 3rd
party components should preferably appear as
separate modules with standardized interfaces.
6. Product model and configuration model can be
created simultaneously, with a focus on stable and
well known components. For yet not finally
designed components dummy classes with estimated
functionalities can be created.
7. In order to handle the complexity of the knowledge
base, the configuration model needs to follow the
same objectives as the product structure, namely;
(a) the use of generic and modular yet encapsulated
configuration classes with little cross related
constraints (standardized interfaces), (b) the
implementation of standardized and decreased attribute
ranges.
      </p>
    </sec>
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