<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>P2PIE: A NEW ENTERPRISE APPLICATION INTEGRATION SOLUTION</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Jörgen Hanson</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jens Ohlsson</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Nevzat Ertan</string-name>
          <email>nevzat.ertan@sandvik.com</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Paul Johannesson</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Stefan Wernmo</string-name>
          <email>swernmo@gmail.com</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ole Schjødt-Osmo</string-name>
          <email>ole.schjodt-osmo@gmail.com</email>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Shengnan Han</string-name>
          <email>shengnan@dsv.su.se</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tomas Hedlund</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Computer and Systems Sciences, Stockholm University Kista</institution>
          ,
          <country country="SE">Sweden</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Husqvarna AB Stockholm</institution>
          ,
          <country country="SE">Sweden</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Sandvik AB</institution>
          ,
          <addr-line>Stockholm</addr-line>
          ,
          <country country="SE">Sweden</country>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>Yara International Oslo</institution>
          ,
          <country country="NO">Norway</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2015</year>
      </pub-date>
      <fpage>60</fpage>
      <lpage>70</lpage>
      <abstract>
        <p>In order to provide unified and consistent data and functionality, enterprises need to make all their applications work in an integrated manner. However, integration has become more difficult to handle when enterprises extend their business globally, more applications are implemented for supporting business activities, and more computing paradigms are adopted, e.g., cloud, social, and mobile, just to name a few. The state-of-the-art integration solutions have limitations to address the difficulty. In this paper, point to point integration engine-P2PIE, a new integration solution is presented and discussed. The solution combines distributed execution of integration with centralized management console, which innovate the fundamental integration infrastructures of point to point paradigm, and message systems. P2PIE is developed and tested by Sandvik over the decade. The solution has addressed Sandvik's challenges in enterprise application integration. Agility, cost reduction and reliability of this solution are proved.</p>
      </abstract>
      <kwd-group>
        <kwd>enterprise application integration</kwd>
        <kwd>point to point</kwd>
        <kwd>message systems</kwd>
        <kwd>integration solution</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>In order to provide unified and consistent data and functionality, enterprises need to
make all their applications work in an integrated manner. However, integration has
been a difficult task to handle for several reasons. First, integration is highly depended
on specific applications to be integrated, which involves integrating applications of
various kinds, such as custom-built applications based on C++/C#, Java/J2EE,
packaged applications, such as CRM or ERP applications, and legacy applications, for
instances, mainframe CICS or IMS. Second, these applications are usually dispersed
geographically when enterprises expend their business globally. Third, these
applications are mostly operated on various platforms. Fourth, when enterprises increase
cooperation and build up partnerships with other companies, there is a demand for
integrating applications across enterprises.</p>
      <p>
        Over the last one and a half decade, we have witnessed significant evolution in
enterprise application integration (EAI). Integration paradigms have developed from
simple file/data sharing, messaging system, message broker to more complete
integration solution, which has a centralized point of control for increasing the flexibility in
changing and managing integration [
        <xref ref-type="bibr" rid="ref1 ref2">1, 2</xref>
        ]. Message brokers (hub-and .spoke) and
enterprise service buses (ESB) are the two state-of-the-art integration solutions that
are adopted by enterprises [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. The goal of the paradigm evolution has been to
increase reliability, effectiveness, and reduce the time it takes to change and reconfigure
integration solutions, as well lower the cost of integration.
      </p>
      <p>
        The state-of-the-art integration solutions have limitations. This resides partly on
the integration logic for solving an integration problem that is highly distributed in its
nature by centralized software and hardware [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. Furthermore, demands for
integration and complexity of integration are intensified. According to [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], organizations
application portfolios are increasing in complexity by deploying more applications
overall as well as more application functionalities in the cloud, on mobile devices and
in conjunction with external business partners. B2B growth, cloud adaptation (SaaS),
M&amp;A, and consolidation activities are also foreseen to result in increased integration
demands. Furthermore, the demand is accelerated when enterprises are transforming
into digital business. Integrating big data and any things from human, machine and
applications is emerging as the greatest challenge that enterprises have to address. A
new enterprise application integration solution is emerged and developed to handle
the new challenges.
      </p>
      <p>
        Sandvik, a large international company producing metal tools, headquartered in
Sweden, has managed its current and future integration challenges by developing this
new integration solution based on the business demands for agility, cost reduction,
and reliability. The solution is named Point to Point Integration Engine (P2PIE). The
P2PIE solution has been developed independently but some of its features, in
particular the point to point and message mechanisms, are similar to those state-of-the-art
solutions that suggested by [
        <xref ref-type="bibr" rid="ref6 ref7 ref8">6, 7, 8</xref>
        ].
      </p>
      <p>The paper is organized as follows. In section 2, related work for enterprise
application integration is briefly discussed. The case of Sandvik and its motivation for
developing P2PIE are described in section 3. Section 4, P2PIE solutions are discussed,
including its architecture, components, as well the gained values of implementing
P2PIE. The paper ends with discussions and conclusion. Abbreviations used in this
paper are given at appendix A.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Related work</title>
      <p>Enterprise application integration (EAI) is aimed to make applications be able to
communicate with each other. The paradigms for EAI have evolved over time, from
point to point solution, to message brokers (hub-and-spoke), and to enterprise services
bus (ESB)</p>
      <p>
        The integration logic of a point to point integration solution is to connect two
applications which need to integrate with each other [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. This type of communication
has two ends, and does not need to go through a central server to handle the
integration. In a fully integrated enterprise where all applications are connected with each
other, with N applications, there will be ! !!! connections. The advantage of a
!
point to point solution is that it communicate directly between the points. The
disadvantages of this solution are that every point’s integration solution is uniquely built
and that the points as a whole have no overlaying monitoring ability [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>
        The integration logic of message brokers (hub-and-spoke) is built upon message
systems infrastructure [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. This solution can transform, route and queue messages
through a central messaging hub [
        <xref ref-type="bibr" rid="ref10 ref9">9, 10</xref>
        ]. Most of enterprise applications have various
data format, which raise problems in integration. Message broker can solve the
problem by transforming data from different applications into message. The message is
routed through a central messaging hub that enable integration among these
applications [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. The advantage of a message broker is that it offers a centralized integration
solution where the integration logic and error management are collected in one place
[
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. The disadvantage of the solutions is that all communication goes through the
central hub, as the solution grows the more pressure will be put on the hub.
      </p>
      <p>
        An ESB has the same integration logic as message broker. However, ESB
transforms data and route messages by using services for achieving integration goals [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
The services needed are implemented separately and therefore allows applying more
functionality without disturbing the rest of the solution [
        <xref ref-type="bibr" rid="ref10 ref9">9, 10</xref>
        ]. The advantage of an
ESB is that it is flexible, allowing it to grow with the enterprise’s need. The
disadvantage of this solution is that it is complex, as the services are managed separately.
3
      </p>
    </sec>
    <sec id="sec-3">
      <title>Integration problems at Sandvik</title>
      <p>Sandvik, recognized as a world leader in tools and application solutions for the
metalcutting industry, grew through many acquisitions during the period 1995-2005. A
multi-brand strategy and a strong decentralization culture resulted in a legacy
consisting of hundreds of business critical applications on different heterogeneous platforms
and systems. These applications were communicating through various integration
solutions /platforms from different vendors. Which resulted in little synergies between
the main business sectors. Furthermore, most of the integration tasks were completed
within each business sector by using “hard coupled” systems integration logic.
Consequently, integration projects can’t be controlled within budget and completed on
time. Moreover, the clear roles/mandates between central/local organizations can’t be
specified, as well the central monitoring and governance of the enterprise application
integration can’t be done.</p>
      <p>Sandvik followed an approach based on Microsoft BizTalk, an ESB solution. Still,
due to the increasingly higher volumes of data and the synchronous connections to
and from Sandvik’s back end system, there were however still challenges to obtain a
highly reliable environment. An intermediate solution was then to add an
asynchronous queuing approach by IBM Webshere MQ. In this way some of the problems
could be solved but also new ones were introduced, basically depending on the fact;
by adding this MQ component between the sources system / receiving system and
BizTalk, the control over the complete integration chain from the source system to the
receiving system get lost. All these experiences called for development of a new
solution that is robust, reliable, flexible, easily scalable and cost efficient.</p>
      <p>In 2005, Sandvik decided to create a common artefact for connecting its backend
systems to MQ, and this artefact would be governed and monitored centrally. While
doing so, it was discovered that it would be fairly easy to make this artefact adapter
based. This meant that a component was built that was distributed to all servers where
it was needed, which had the capability of transferring data between any two
endpoints. It also has the capability of remote management, and the source or destination
endpoints could be changed from the central Management Console just by changing
configurations. P2PIE solution, thus, is developed for solving EAI problems at
Sandvik.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Point to Point Integration Engine -P2PIE</title>
      <p>The P2PIE solution retains all benefits in a hub and spoke architecture by keeping
management central (including configuration, control and monitoring), but
decentralizing the Integration Engine in order to optimize efficiency and reduce complexity.</p>
      <p>The key components of P2PIE solution include integration engine, central
management console, and a central database. The architecture of P2PIE is shown in Figure
1.</p>
      <p>The P2PIE is installed on the same physical servers that serves as endpoints in an
integration scenario. On a conceptual level, this can be seen as a big distributed
“virtual broker”, fully operated from a central management console. The individual
distributed Integration Engines can act as both sources and destinations in integration
scenarios.</p>
      <p>The P2PIE in Sandvik handles the integration of applications and uses a MQ to
transport messages between points. The integration line of sight is the physical reach
of the integration components (integration engines). P2PIE connects business
applications as endpoints directly to each other (endpoint to endpoint), thus delivering 100%
line of sight. This differs from how a Broker/ESB sees the communication and
integration between two applications. A Broker/ESB is put in the middle and only sees
what happens with the messages up to the MQ. The line of sight is therefore limited to
that point and there is no control over what happens between the application and the
MQ. This is not delivering transparency into the business applications since the
Broker/ESB can’t see when applications reads or puts something on the queue. This
difference is illustrated in Figure 2.
An “Integration Engine”, which shortly can be described as an adapter based
component that is installed on all servers with software applications that need to
communicate and integrate (Figure 3). The logic is thus executed in the engine and the engine
itself is distributed by installing a software “integration instance”, corresponding to
one service, on each server. Depending on integration scenario the server may have
several instances. The source-destination connections are set up by DLL-based
plugins in the integration engine. One plug-in for the source application but an arbitrary
number of plug-ins for the needed destination applications. Also other types of
plugins than source-destination plug-ins can be used, e.g. pre-processors or
postprocessors for specific tasks. e.g. XSLT-transforming, advanced routing, or any type
of enhancement to the inbound message. All plugins are stored in the central
Repository and are distributed on a need-to-have basis.</p>
      <p>Fig. 3. Distributed Integration Engine within the P2PIE solution.</p>
      <p>Note: 1. Source, 2. Destination 1..n, 3. Pre-processor 1..n, 4. Post-processor 1..n
P2PIE also provides an API so that an external application can send, or retrieve
messages via a P2PIE instance. If an exception occurs, it is translated into a WMI
event and can thus be monitored by SCOM. Each integration point keeps track of
each event, when it starts, stops, or throws an exception and distributes the
information to the central repository in nearly real time. The system monitors each step in
the integration chain and alarms during deviation from the predetermined thresholds.
This means that an error in the integration-chain can be quickly found and addressed
to the individuals with the right skills for the task.</p>
      <p>P2PIE is a distributed integration. However, it possesses the possibility to do
service oriented integration. Since service oriented integration doesn't necessarily
need to use a broker or ESB, which works well in P2PIE solution. The scalability and
the resource capability of each server are not an issue in P2PIE. Sandvik monitors
each server to measure its utilization. The evidence shows that capability deficiency is
rarely happened in servers.
4.2</p>
      <sec id="sec-4-1">
        <title>Central Management Console</title>
        <p>A central “Management Console”, where all integration engines are governed and
monitored remotely and centrally. The GUI of the central management console of
P2PIE is shown in Figure 4. The central console configure the Integration Engine, and
thus integrations are created. All configurations made are stored into the central
databases and to all Integration Engines that taking part in integrations. From the central
management console, every execution related to an integration is controlled, including
deployment, start/stop, monitoring, alerts, notifications and exception handling.
4.3</p>
      </sec>
      <sec id="sec-4-2">
        <title>Database</title>
        <p>P2PIE has a central database running on SQL server. This database does not have any
run-time dependencies to the distributed Integration Engines. The database saves a
copy of all configurations done, a repository for all plug-ins including their history,
and central log storage.
• Configuration</p>
        <p>This is where a central copy of all configurations are persisted
• Repository</p>
        <p>The repository is the storage area for all plugins that are used in the P2PIE
solution. The history of plugins is also kept so that a rollback of configuration is
possible.
• Logs</p>
        <p>Whenever an integration is executed, i.e. one business application sends and/or
receives information from another business application, an information-log is created
and stored in the central log database.
P2PIE has matured and grown internally at Sandvik. It now handles all integrations
where BizTalk is not involved and manages more than ten times the daily load of the
BizTalk environments. This is by far the largest integration solution at Sandvik.</p>
        <p>P2PIE is installed on more than 250 servers worldwide at Sandvik and manages
more than 2,500 integration points, handling more than 500 000 transactions/day. The
solution makes integration through configuration possible on the following systems
and platforms: BizTalk, .NET, MS SQL Server, SAP, IBM MQSeries, Lotus Notes,
Java, AS/400 and IBM mainframe.</p>
        <p>The development and implementation of the P2PIE solution has brought significant
positive effects and business value to Sandvik. The business demands for enterprise
application integration on agility, reliability, and cost reduction have achieved:
• Improved agility: P2PIE reduces the change and implementation times more than
30%. This is possible both as integrations are more direct between two endpoints,
which leading to reduced complexity. Moreover, integration instances can be
reused for configuration, which taking less time than coding again in creating an
integration.
• Increased reliability: P2PIE improves monitoring, enhances identification of
exceptions, and handles exceptions by better and more efficient tools. The reliability
of the integration related to the data flow and the content consistency have
increased significantly. In 2012 the P2PIE solution handled more than 120 000 000
messages with an average of 7 exceptions per 100 000 messages. Volume
evolution and reliability over time of P2PIE at Sandvik is shown in Figure 5.</p>
        <p>Messages  </p>
        <p>Excep0ons  
25  
20  
15  
10  
5  
0  
s 
e
g
a
s
s
e
0m 
0
00 
0
/s1  
n
o
0
p
e
c
x
E
• Reduced cost: P2PIE reduces cost in two aspects. Firstly, it reduces cost in setting
up integrations in a new system development project. The integration cost in a new
system development project, e.g., ERP system, was estimated at 35% of the total
project budget in 2002. This was reduced to 25% 2007, and 15% 2012. Secondly,
P2PIE reduces the annual running cost for operations and maintenance of the
current legacy integration environment. Due to the large reduction of vendor
integration platforms/suites and cost avoidance of several BizTalk instances, the
percentage of the integration related cost in systems operations &amp; maintenance was
reduced from roughly 21% 2002 to 3% 2007, and even lower at 1,5% at 2012. These
savings were generated from reduced maintenance costs, less hardware cost, and
more reuse and configuration of implemented integrations.
5</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>Discussion and conclusion</title>
      <p>In this paper, P2PIE, a new integration solution developed by Sandvik, is presented
and discussed. The implementation of P2PIE has achieved business values for
Sandvik that the company gains the capability to response changes efficiently and to
pursue business opportunities effectively. P2PIE solution is aimed to lower cost,
improve agility and reliability.</p>
      <p>P2PIE integration solution is better aligned with the nature of managing a data
flow across an IT landscape in enterprises. The logical flow schemes and control
mechanisms are kept at a central console, while the physical point to point integration
engine is implemented by taking into account the distributed nature of integration.
Thereby it pursues efficient execution of the real time operational data flow. By doing
so, data are allowed to flow the shortest and most cost effective way between the
actual applications and databases.</p>
      <p>Despite its simplicity and alignment with the nature of integration (with
requirements for central control but distributed execution of data flow), the P2PIE solution
makes significant contribution to EAI research and practice. Although the P2PIE
integration solution is built upon the well- known and proven paradigm of point to
point integration paradigm and message systems, the solution innovates EAI by using
distributed and decentralized logic rather than the state-of-the-art centralized
approach. This underlines the originality and innovativeness of P2PIE integration
solution. The values achieved by implementing P2PIE at Sandvik over the years also
bring strong empirical evidence for demonstrating the capability of the solution in
tackling integration challenges. The novelty of the P2PIE integration paradigm is its
distributed nature, where business applications send and receive data directly without
passing a centralized hub, which also delivers the capability of full transparency of
integration flows.</p>
      <p>In the recent years, the need to manage a growing demand for integration is
increased and intensified. Since many companies have to integrate applications used by
different partners on B2B value networks, to migrating to emerging computing
paradigm, e.g. cloud, mobile, social, big internet of things, cyber physical systems, just to
name a few. Companies have also to meet demand for services to be available
everywhere on every new devices. P2PIE is an innovative solution that can be used for
addressing these integration challenges. Future research is to demonstrate and
evaluate the P2PIE solution in additional instantiations both at large enterprises as well as
medium sized companies.</p>
    </sec>
    <sec id="sec-6">
      <title>Appendix: Abbreviations</title>
      <p>A2A - Application to Application
B2B – Business to Business
CICS - Customer Information Control System (mainly run on IBM mainframe)
CRM – Customer relationship management
DLL - Dynamic-Link Library
ESB – Enterprise Service Bus
EAI – Enterprise Application Integration
ERP- Enterprise Resource Planning
GUI – Graphical User Interface
HTTP - Hypertext Transfer Protocol
IMS - IBM Information Management System
M&amp;A – Mergers and Acquisitions
MQ - Message Queueing
P2PIE – Point to Point Integration Engine
R&amp;D – Research and Development
SaaS – Software as a service
SCOM - System Center Operations Manager
SOAP - Simple Object Access Protocol or Symbolic Optimal Assembly Program
SQL - Structured Query Language
XML - Extensible Markup Language
XSLT - XML (Extensible Markup Language) Stylesheet Language for
Transformations
WMI - Windows Management Interface</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <surname>Ferreira</surname>
            ,
            <given-names>D.R.</given-names>
          </string-name>
          :
          <source>Enterprise Systems Integration: A Process-Oriented Approach</source>
          . Springer, Heidelberg (
          <year>2013</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <surname>Roshen</surname>
          </string-name>
          , W.:
          <article-title>SOA-based enterprise integration: A step-by-step guide to services-based application integration</article-title>
          .
          <source>McGraw-Hill</source>
          , New York (
          <year>2009</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          3.
          <string-name>
            <surname>Alonso</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Casati</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Kuno</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Machiraju</surname>
            ,
            <given-names>V.</given-names>
          </string-name>
          :
          <source>Web services: Concepts</source>
          ,
          <source>Architectures and Application</source>
          . Springer, Heidelberg (
          <year>2004</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          4.
          <string-name>
            <surname>Linthicum</surname>
            ,
            <given-names>D.S.:</given-names>
          </string-name>
          <article-title>Enterprise application integration (Addison-Wesley information technology series)</article-title>
          .
          <source>Addison-Wesley</source>
          , Reading (
          <year>2000</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          5.
          <string-name>
            <surname>Lheureux</surname>
            ,
            <given-names>B. J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Pezzini</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Thompson</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Altman</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Sholler</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Schulte</surname>
            ,
            <given-names>W. R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Malinverno</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Knipp</surname>
            ,
            <given-names>E</given-names>
          </string-name>
          : Predicts 2013
          <string-name>
            <given-names>: Application</given-names>
            <surname>Integration. Gartner</surname>
          </string-name>
          (
          <year>2012</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          6.
          <string-name>
            <surname>Kupsch</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          and
          <string-name>
            <surname>Werth</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          :
          <article-title>Integrating Business Processes with Peer-to-Peer Technology</article-title>
          . In: Konstantas,
          <string-name>
            <given-names>D.</given-names>
            ,
            <surname>Bourrières</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.P.</given-names>
            ,
            <surname>Léonard</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            ,
            <surname>Boudjlida</surname>
          </string-name>
          , N. (eds.)
          <source>Interoperability of Enterprise Software and Applications</source>
          , pp.
          <fpage>277</fpage>
          -
          <lpage>288</lpage>
          . Springer, London (
          <year>2006</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          7.
          <string-name>
            <surname>Lin</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Maheshwari</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          :
          <article-title>Agent-Based Middleware for Web Service Dynamic Integration on Peer-to-Peer Networks</article-title>
          . In: Zhang,
          <string-name>
            <given-names>S.</given-names>
            ,
            <surname>Jarvis</surname>
          </string-name>
          ,
          <string-name>
            <surname>R</surname>
          </string-name>
          . (eds.)
          <source>AI 2005: Advances in Artificial Intelligence. LNCS</source>
          , vol.
          <volume>3809</volume>
          , pp.
          <fpage>405</fpage>
          -
          <lpage>414</lpage>
          . Springer, Heidelberg (
          <year>2005</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          8.
          <string-name>
            <surname>Pallickara</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          and
          <string-name>
            <surname>Fox</surname>
          </string-name>
          , G.:
          <article-title>NaradaBrokering: A Distributed Middleware Framework and Architecture for Enabling Durable Peer-to-Peer Grids</article-title>
          . In: Endler,
          <string-name>
            <given-names>M.</given-names>
            and
            <surname>Schmidt</surname>
          </string-name>
          , D. (eds.)
          <source>Middleware</source>
          <year>2003</year>
          , LNCS, vol.
          <volume>2672</volume>
          , pp.
          <fpage>41</fpage>
          -
          <lpage>61</lpage>
          . Springer, Heidelberg (
          <year>2003</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          9.
          <string-name>
            <surname>Gold-Bernstein</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Ruh</surname>
            ,
            <given-names>W.A.</given-names>
          </string-name>
          :
          <article-title>Enterprise integration: The essential guide to integration solutions</article-title>
          .
          <source>Addison-Wesley</source>
          , Boston (
          <year>2005</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          10.
          <string-name>
            <surname>Brahm</surname>
          </string-name>
          , G.:
          <article-title>ESB vs EMB</article-title>
          . http://esb-nitin.blogspot.se/
          <year>2009</year>
          _07_01_archive.html (
          <year>2009</year>
          )
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>