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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>SPICE: A Generic Model for Interoperability Assessment?</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Wided GUEDRIA</string-name>
          <email>wided.guedria@tudor.lu</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>EE Unit, Henri Tudor Public Research Center</institution>
          ,
          <country country="LU">Luxembourg</country>
        </aff>
      </contrib-group>
      <fpage>27</fpage>
      <lpage>38</lpage>
      <abstract>
        <p>Measuring interoperability implies establishing measures of merit to evaluate the degree of interoperability between systems. This is the purpose of so-called maturity models, describing the stages through which systems should evolve to reach higher completeness in the realization of a given objective. This paper reviews the main maturity models for interoperability, comparing the di erent aspects of these models to ISO/IEC 15504 model (also known as SPICE), which de nes a framework for processes assessment. We highlight the existing links, showing that ISO/IEC 15504 can be used as a generic model from which existing interoperability maturity models could be derived.</p>
      </abstract>
      <kwd-group>
        <kwd>Capability</kwd>
        <kwd>maturity</kwd>
        <kwd>interoperability</kwd>
        <kwd>assessment</kwd>
        <kwd>model</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>Nowadays, IT as well as human systems evolve in a worldwide heterogeneous
environment and work in network. For enterprises, operating in such
environment requires exibility and co-operations between other enterprises, sharing
their core competencies in order to exploit the market opportunities. Exchanges
are needed for both operational control, and to a larger extend for the decision
making process during the establishment of cooperation, including opportunity
exploration, co-operation planning and implementation. Therefore, the ease of
communication between the people involved and the quality of inter-operation
between the supporting information and communication systems play a key role
in such co-operations. A major issue in global collaboration and co-operation of
enterprises is the management of the interoperability problems.</p>
      <p>
        In this work, Interoperability is considered from a systemic perspective where it
is rst viewed as a problem to solve: An interoperability problem appears when
two or more incompatible systems are put in relation [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Then, it is seen as a
goal to reach, where Interoperable systems operate together in a coherent
manner, removing or avoiding the apparition of related problems. Last, if we consider
a process view of interoperability, we may de ne it as the process allowing an
enterprise interoperating with its partners (existing or future ones), by solving
existing problems and/or previnting potential ones.
      </p>
      <p>
        According to [
        <xref ref-type="bibr" rid="ref13 ref4">13, 4</xref>
        ], there are three kinds of interoperability problems:
Conceptual, Technological and Organizational. Conceptual problems are mainly
concerned with the syntactic and semantic incompatibilities of information to be
exchanged or to be used during an interoperation. Technological problems refer
to the use of computer or ICT (Information and Communication Technologies)
to communicate and exchange information (i.e. architecture &amp; platforms,
infrastructure). These problems concern the standards to use, store, exchange,
processes or computerized information. Organizational problems relate to the
de nition of responsibilities and authorities so that interoperability can take
place under good and well-established conditions. In order to quickly overcome
these interoperability problems and thus support enterprises to better
interoperate with their partners, clients, providers, etc.; Enterprise Interoperability (EI)
requires being assessed and continuously improved. Interoperability can be
measured in two ways: a priori where the measure relates to the potentiality of a
system to be interoperable with a possible future partner whose identity is not
known at the moment of evaluation, a posteriori where the measure relates to
the compatibility measure between two (or more) known systems willing to
interoperate.
      </p>
      <p>
        One of the assessment methods consists in using maturity models. A maturity
model is a framework that describes for a speci c area of interest a number of
levels of sophistication at which activities in this area can be carried out [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. Many
maturity models have been proposed in the litterature such as : LISI (Levels of
Information System Interoperability) [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ], OIM (Organizational Interoperability
Model) [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ], LCIM (Levels of Conceptual Interoperability Model) [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ], MMEI
(Maturity Model for Enterprise Interoperability) [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ], etc. Unfortunately, each
one of these maturity models proposes to assess interoperability from a di erent
perspective, with a di erent approach and metrics.
      </p>
      <p>
        Very little e ort has been made in designing a generic model assessing
interoperability that an enterprise may instantiate to its context and use to its speci c
needs. In light of these, the main research question addressed by this paper is:
What are the di erences between maturity models that are dedicated to
interoperability and a maturity model such as ISO/IEC 15504 standard, also known
as SPICE (Software Process Improvement and Capability dEtermination) [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], if
we consider interoperation between partners and/or preparing interoperability
as processes. One of the implications of the previous research question touches
upon the possibility to have a generic model assessing interoperability.
To deal with this research question, we rst review the main existing
interoperability maturity models in order to compare their di erent levels with SPICE
standard, considered here as a reference model. With this comparison, we aim
at showing that SPICE can be used to form a generic model that can be
instantiated in di erent contexts of interoperations.
      </p>
      <p>
        The reminder is structured as follows. In section 2, we present the reference
model (SPICE). In section 3, we survey the main maturity models for each type
of interoperability [
        <xref ref-type="bibr" rid="ref13 ref4">13, 4</xref>
        ]: The LISI (Levels of Information System
Interoperability) model [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] for the technical interoperability, the LCIM (Levels of Conceptual
Interoperability Model) model [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] for the Semantic Interoperability, the OIM
(Organizational Interoperability Model) model [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] for organizational
interoperability, we nally present the MMEI (Maturity Model for Enterprise
interoperability) [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ], that considers the three aspects of interoperability in an enterprise
context. With the description of these maturity models, we highlight the links
between each model and the reference model. In section 4, we classify the
reviewed models followed by a brief discussion. Finally we conclude in section 5,
by highlighting future work.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2 Reference Model</title>
      <p>
        SPICE (Software Process Improvement and Capability dEtermination) [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] is an
international standard for software process assessment, developed by the Joint
Technical Subcommittee between ISO (International Organization for
Standardization) and IEC (International Electrotechnical Commission).
      </p>
      <sec id="sec-2-1">
        <title>De nition</title>
        <p>
          In [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ], a process is de ned as a set of activities correlated or interactive that
transforms inputs into outputs.
        </p>
        <p>SPICE de nes six levels of capability, from Level 0 to Level 5, as shown in
table 1. The capability of processes is measured according to nine attributes:
Process Performance, Performance Management, Work Product Management,
Process De nition, Process Deployment, Process Measurement, Process Control,
Process Innovation, Process Optimization. For each process attribute, one or
more generic practices are de ned, which are further elaborated into practice
indicators to aid assessment performance. Each process attribute is assessed on
a four-point (N-P-L-F) rating scale:
{ N- Not achieved (0 - 15%)
{ P- Partially achieved (&gt; 15% - 50%)
{ L- Largely achieved (&gt; 50% - 85%)
{ F- Fully achieved (&gt; 85% - 100%).</p>
        <p>
          As an application of SPICE requirements, the CMMI model (Capability
Maturity Model Integration) [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ] was proposed. The CMMI is a maturity model that
can be used to guide process improvement across a project, a division, or an
entire organization. Though CMMI is well known, it is an instance of SPICE,
which we will not discuss here. For more details, see [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ].
        </p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3 Maturity Models for Interoperability</title>
      <p>In this section, we study the existing maturity models for interoperability and
discuss their correspondances with SPICE.</p>
      <sec id="sec-3-1">
        <title>3.1 LISI : Levels of Information System Interoperability</title>
        <p>
          The LISI maturity model [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ] identi es the stages through which systems should
logically progress or "mature" in order to improve their capabilities to
interoperate. Five levels are identi ed by terms that describe both the level of
interoperability and the environment in which it occurs, as shown in table 2. Within each
        </p>
        <p>Data and applications are fully shared and
distributed. Data has a common interpretation
regardless of format.</p>
        <p>Information is exchanged between independent
applications using shared domain-based data
models.</p>
        <p>Logical data models are shared across systems.</p>
        <p>Simple electronic exchange of data.</p>
        <p>Manual data integration from multiple systems.
level, LISI identi es additional factors that in uence the ability of systems to
interoperate. These factors comprise four attributes: Procedures, Applications,
Infrastructure, and Data (PAID). PAID provides a method for de ning the set
of characteristics required for exchanging information and services at each level.
It de nes a process that leads to interoperability pro les and other products.
LISI focuses on technical interoperability and the complexity of interoperations
between systems.</p>
        <p>As it can be noticed, the LISI model meets the SPICE requirements and can be
instanciated from the SPICE model in the speci c context of technical
interoperability of systems. Indeed, the purpose of a system using LISI, is to have the
highest level of technical interoperability. So, the process to consider here is the
technical interoperability. Each de ned level in the LISI model can be matched
with a level of the SPICE standard, as follows:
{ Isolated interoperability level can be associated to SPICE Incomplete process
level. On the one hand, the SPICE incomplete process level is the result of
assessing a process that failed to attain the purpose of the process. On the
other hand, the LISI Isolated level is concerned with isolated systems in a
manual environment with no electronic links between them : The purpose of
the technical interoperability as a process is not achieved.
{ Connected interoperability level can be associated to SPICE Performed
process level. On the one hand, the SPICE Performed process level is the result of
assessing a process that achieved its purpose but in a non rigorously planned
and tracked way. On the other hand, the LISI Connected interoperability level
is concerned with connected systems in a peer-to-peer environment with some
form of simple electronic exchange of data and a little capacity to fuse
information. So the technical interoperability as process is achieved but in a non
rigorously planned or tracked. In that context, SPICE Performed process level
can clearly be matched with the Connected interoperability level.
{ Functional interoperability level can be associated to SPICE Managed
process level. Indeed, the SPICE Managed process level is the result of assessing
a process with an acceptable quality within de ned timescale. On the other
hand, the LISI Functional interoperability level is concerned with functional
systems in a distributed environment which required a timely processing of
the information from the involved system distributed entities. In that
context the SPICE Managed process level can be matched with the Functional
interoperability level.
{ Domain based interoperability level can be associated to SPICE Established
process. In fact, the SPICE Established process level is the result of assessing
a process that is performed and managed using a de ned process based upon
good software engineering principles. On the other hand, the LISI Domain
based interoperability level is concerned with integrated systems in an
integrated environment which requires common business rules and processes as
well as database to database interactions. In that context the LISI Domain
based interoperability level can be matched with the SPICE Established level.
{ Enterprise-based interoperability level can be associated to SPICE Predictable
process level. In fact SPICE Predictable process level is the result of assessing a
process that is performed consistently in practice within de ned control limits
to achieve its goals. On the other hand, the LISI Enterprise-based
interoperability level is concerned with interoperable systems in a universal environment,
in this context, data and application are fully shared and distributed, so the
technical interoperability as a process is predictable in a SPICE meaning.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2 LCIM : Levels of Conceptual Interoperability Model</title>
        <p>
          In [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ] the Levels of Conceptual Interoperability (LCIM) Model was proposed
to address levels of conceptual interoperability that go beyond technical models
like LISI.
        </p>
        <p>The model is intended to be a bridge between conceptual design and technical
design. The focus lies in the data to be interchanged and the interface
documentation that is available. The layers of the LCIM model are shown in table 3.
With the same assumption that interoperability is a process, the LCIM model
Semantic connections are made apparent via a
documented conceptual model underlying components.</p>
        <p>Use of data is de ned using software engineering
methods like UML.</p>
        <p>Common reference model with the meaning of data
unambiguously described.</p>
        <p>Shared protocols between systems with data
accessible via interfaces.</p>
        <p>Black boxes components with no interoperability or
shared data.
would eventualy meet the de ned requirements in SPICE standard in a
conceptual interoperability context. Indeed, with LCIM, the purpose is to have the
highest level of semantic interoperability.</p>
        <p>Each LCIM maturity level can have its corresponding level in SPICE:
{ Isolated systems level corresponds Incomplete process level. Indeed, the result
of the interoperability assesssment at this LCIM level is the non
interoperability or shared data. With the SPICE incomplete process level, the result would
be the failure to attain the purpose of the process. In that context, LCIM
Isolated systems level matches with SPICE Incomplete process level.
Documented Data matches with Performed Process. Indeed, the result of
assessing the semantic interoperability between systems, at the LCIM level, is
the existence of shared protocols between systems with accessible data (via
interfaces) but with no common reference model. With the SPICE level, a
process which achieved its purpose but in a non common, planned way. In
this context, we see clearly the correspondance between the two levels.
{ Aligned Static Data can be related to Managed Process. At the LCIM level,
the result of the interoperability assessment is a common reference model,
a managed data but with di erent interpretations in systems. On the other
hand, at the SPICE level 2, we have as assessment result a managed process
with acceptable quality. In this context these two levels can be matched.
Aligned Dynamic Data corresponds to Established Process in SPICE. Indeed,
the interoperability assessment at this level is the de ned use of data using
uni ed models. On the other hand the SPICE Established process level
requires a performed, managed, de ned process. Hence, the two levels of the
two models can be matched.
{ Harmonized Data level matches with Predictible Process level in SPICE.
Indeed, the interoperability assessment at this level is a common conceptual
model and a semantic consistency. On the other hand, we nd SPICE
predictible process level which requires the achievement of the process goal within
de ned control. In this contect, Harmonized Data level can be related to
SPICE level 4.</p>
        <p>It is relevant to notify that the optimisation and maintenance aspects are not
taken into account in this model, as in SPICE (level 5).</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3 OIM : Organizational Interoperability Model</title>
        <p>
          The Organizational Interoperability Maturity Model [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ] de nes the levels of
organisational maturity that describe the ability of organisations to interoperate.
Five levels are identi ed, as depicted in table 4. The OIM model meets also the
de ned requirements in SPICE standard in an organizational interoperability
context. Indeed, with the OIM model, the process to evaluate would be the
organizational interoperability. Each maturity level of the OIM model can have
its corresponding SPICE level:
{ Independent level can be associated to SPICE Incomplete process level. Indeed,
at this level, organizations are independent and work without any interaction.
The organizational interoperability as process is incomplete. In this context
the OIM Independent level matches with SPICE Incomplete process level.
{ Ad hoc level matches with SPICE Performed process level. Indeed, at this level
the interoperability is done in an ad hoc manner and specif arragements are
unplanned, so with the organizational interoperability process can be achieved
but in a non rigorously planned way. In this context we can clearly notice that
Ad hoc level can be matched with SPICE Performed process level.
{ Collaborative level can be related to SPICE Managed process level. In order
to reach this level, the organization should have a recognized framework to
support interoperability in an acceptable way. At this level organizations are
still distinct. In that context the SPICE Managed process level, which requires
the process achievement in an acceptable quality, matches with the ( OIM
Collaborative)level.
{ Integrated level matches with SPICE Established process level. Indeed,
organizations reach this interoperability level when they have shared goals and
        </p>
        <p>Uni ed The organisation is interoperating on a continuing
basis. Command structure and knowledge basis are
shared.</p>
        <p>Integrated Shared value systems and goals, a common
understanding to interoperate however there are still
residual attachments to a home organisation.</p>
        <p>Collaborative Recognised interoperability frameworks are in place.</p>
        <p>Shared goals are recognised. Roles and responsibilities
are allocated but the organisations are still distinct.</p>
        <p>Ad hoc Some guidelines to describe how interoperability will
occur but essentially the speci c arrangements are
still unplanned. Organisations remain entirely
distinct.</p>
        <p>
          Independent Organisations work without any interaction.
Arrangements are unplanned and unanticipated. No formal
frameworks in place. Organisations are able to
communicate for example via telephone, fax and personal
contact in meetings.
a common understanding to interoperate. At this level the interoperability
framework should be be in place and practiced even the residual attatchements
to a home organization. These requirements to reach the OIM Integrated level
correspond with those de ned at the SPICE Established process, where a
performed and managed process using a de ned framework is required.
{ Uni ed level matches with SPICE Predictable process level. This level, which
is a goal for many organizations, requires organization to be interoperating
on continuing basis. From the SPICE perspective, the requirement to be at
predictible level, a process has to be de ned, performed and consistently in
practise.
3.4 MMEI : Maturity Model for Enterprise interoperability
The Maturity Model for Enterprise Interoperability (MMEI) [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ] is a maturity
model de ned within an a priori context of interoperability. It allows companies
to evaluate their potentiality to interoperate, in order to know the probability
that they have to support e cient interoperation and to detect precisely the
weaknesses that are sources of interoperability problems.
        </p>
        <p>
          MMEI de nes ve levels of Enterprise interoperability. For each one of these
maturity levels, previous maturity models and the way they de ne their levels have
been considered and adapted to match an a priori assessment context. MMEI
levels are rst speci ed and a detailed description for each level is given. Table
5 gives an overview of the MMEI levels. Each MMEI maturity level is described
by an mn matrix M = [Pi;j ]m n , where m is the number of interoperability
aspects (i.e. conceptual (semantic and syntactic), technical, organizational) and
n is the number of the enterprise concerns (i.e. business, process, service and
data). These two dimensions constitute the problem space of enterprise
interoperability. Pi;j is the description of the criteria that an EI concern should meet
to avoid interoperability barriers and acquire the target maturity level, see [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ]
for more details. Considering conceptual, organizational and techical
interoperabilities as independent processes, interoperability as assessed by MMEI can be
considered as a process composed by three sub-processes: conceptual, technical
and organizational. Moreover, MMEI is de ned in an a priori context (see
section 1); hence the process here is concerned with preparing interoperability and
not interoperating with an existing partner, as is the case for the other maturity
models. Given that, each MMEI maturity level can also have its corresponding
level in SPICE as follows:
{ At MMEI level 0, the enterprise is concerned by ad-hoc interoperability
capabilities or no will to interoperate. This level can be matched with Level 0
or Level 1 of SPICE. Indeed if the enterprise has the ability to interoperate
in an ad-hoc manner with another partner, then, the Interoperability process
is achieved even though this is not rigorously planned and tracked. However,
if the enterprise has no will to interoperate, then we assume that there is a
general failure to attain the purpose of the process and MMEI Unprepared
level is then matched with to Incomplete process in SPICE.
{ At MMEI level 1, there is a capability of properly modelling and describing
systems to prepare interoperability. This corresponds to the Managed process
level in SPICE where the process delivers work products of acceptable quality
(here models).
{ At MMEI level 2 the enterprise is able to make changes to align to common
formats or standards. This can be matched with level 3 in SPICE where the
process is performed and managed using a de ned process. Indeed, we assume
that a enterprise has to have a de ned process in order to be able to align
to standards and make changes without problems to prepare itself to future
interoperations.
{ At MMEI level 3, the enterprise is able to perform needed mappings with
multiple heterogeneous partners. This corresponds to Predictable process in
SPICE, where the process is performed within de ned control limits to achieve
its goals.
{ At level 4, the enterprise has the ability of negotiating and dynamically
accommodating with any heterogeneous partner. Hence the process is optimized
and the enterprise is able to interoperate on the y to meet its current and
future business needs, which corresponds to the level 5 in SPICE.
        </p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4 Discussion</title>
      <p>The SPICE standard and the other maturity models presented above, aim at
helping an organization, enterprise or a system to improve the way it does
business or co-operates with other partners.</p>
      <p>
        Each available improvement approach focuses on a speci c part of the
business. While the ISO/IEC 15504 provide a generic framework and an assessment
model for proccesses, other maturity models establish measures to evaluate the
interoperability degree in di erent context : the LISI model deals with only the
technical level of interoperability, the LCIM model addresses the Semantic
aspect, the OIM model covers the organizational aspect. Since we postulate that
interoperability is a process among others in an organization, we have seen along
the paper how each maturity level of the studied models can be matched with
the capability levels of SPICE. This leads us to the conclusion that SPICE can
be used as a generic model for interoperability assessment. This can be
thereafter, instanciated in the speci c domain and cover all kinds of interoperability.
In table 6, we give the correspondance of each maturity model to the domain
it covers, taking as reference the descriptions provided in previous sections and
the classi cation done on interoperability in [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] and [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ].
      </p>
    </sec>
    <sec id="sec-5">
      <title>5 Conclusion</title>
      <p>In this paper, we have reviewed some maturity models assessing
interoperability capability with a di erent view. LISI (Levels of Information System
Interoperability) has been studied for technical interoperatbility assessment, LCIM
(Levels of Conceptual Interoperability Model) for semantic interoperability, OIM
(Organizational Interoperability Model) for Organizational interoperability and
MMEI (Maturity Model for Enterprise Interoperability) for Enterprise
Interoperability.</p>
      <p>
        Assuming that interoperability can be considered as a process that need a
particular attention within an enterprise, we have compared these maturity
models towards the ISO/IEC 15504 (SPICE) reference model. This comparison has
shown the need for harmonisation to have a generic standard of maturity.
As perspective, SPICE will form the backbone of our future investigation. We
will thereafter refer to some of the presented maturity models; in particular, the
Maturity Model for Enterprise Interoperability (MMEI), in order to establish a
general framework for system interoperability [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ], allowing enterprises to assess
interoperability from a priori as well a posteriori context.
      </p>
    </sec>
  </body>
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