DEFINING THE SEMANTICS OF IT SERVICE MANAGEMENT
MODELS USING OWL AND SWRL
María-Cruz Valiente, Daniel Rodríguez
Computer Science Department, University of Alcalá, Polytechnic Building, Ctra. Barcelona km. 33.6, 28871
Alcalá de Henares (Madrid), Spain
Cristina Vicente-Chicote
Departamento de Tecnologías de la Informacion y las Comunicaciones, Universidad Politécnica de Cartagena
30202 Cartagena (Murcia), Spain
Keywords: Ontologies, Knowledge representation, Service process modelling, OWL, SWRL, ITSM, and ITIL.
Abstract: Service management is a set of specialized organizational capabilities that provide value to customers in the
form of services. Many organizations are aware of the need to adopt best practices in order to create an
effective IT Service Management (ITSM) for enabling Business and IT integration. However, the reuse and
interchange of service models is still quite limited in the area of IT service support due to the problems in
connecting with natural language. In this context, this paper presents the ITIL-based Service Management
Model aimed at capturing ITSM best practices by means of a formal ontology-based business DSL
(Domain-Specific Language). We show how this DSL can be formally represented adopting the Web
Ontology Language (OWL) and the Semantic Web Rule Language (SWRL). This ontology will precisely
define the semantics associated to IT service management models, enabling different tools to interchange
them without ambiguities. These models will be defined just in terms of the business logic, without any
architectural or platform-specific consideration. That is, according to the OMG's four-layered architecture,
the proposed model could be placed at a CIM level.
1 INTRODUCTION
IT Service Management (ITSM) is one of the fastest
growing fields nowadays that includes a set of
specialized organizational capabilities and a
professional practice supported by an extensive body
of knowledge, experience and skills for providing
value to customers in the form of services. However,
the complexity of both service management and the
development of the supporting information systems
is still a challenging problem in the industry.
In this paper, we study how current advances in
the area of ontologies, domain-specific modelling
languages and model transformations can be used in
the context of IT service support.
Our research goals are to demonstrate: 1) how
the knowledge of ITIL (Information Technology
Infrastructure Library), the best practice guidance in
ITSM, can be captured and formally described in a
business Domain-Specific Language (DSL) by
means of an ontology, and 2) how this ontology-
based DSL can also be used as basis for building a
variety of ITIL-compliant information systems that
underpin the IT services applying a model-driven
approach.
We aim at translating perceptions (semantics) of
the “real-world” expressed in natural language to an
ontology which is a formal representation of the IT
service management domain. The proposed ontology
defines an optimal management of IT services that
enables to draw inferences and automated reasoning.
Due to their deep semantic support, the resulting
specifications can be reused and interchanged
among different tools, avoiding ambiguities,
uncertainties, and contradictions. Also, as a DSL,
our ontology can be used in the area of Software
Engineering addressing the process of domain
modelling. Therefore, we can use the ontology as a
description of a formal DSL to obtain lower level
domain models by means of (automated) model
378
Valiente M., Rodríguez D. and Vicente-Chicote C..
DEFINING THE SEMANTICS OF IT SERVICE MANAGEMENT MODELS USING OWL AND SWRL.
DOI: 10.5220/0003082503780381
In Proceedings of the International Conference on Knowledge Engineering and Ontology Development (KEOD-2010), pages 378-381
ISBN: 978-989-8425-29-4
Copyright
c
2010 SCITEPRESS (Science and Technology Publications, Lda.)
transformations. These target models will describe
high-level requirements of software systems that
implement the tasks defined as part of the IT service
management models.
The rest of this paper is structured as follows.
Section 2 covers the background. Section 3
summarizes the processes we followed for creating
an ontology from ITSM best practices. We describe
how constraints can be modelled and executed in
Section 4. Finally, we conclude in Section 5 with
some final remarks and outlines future work.
2 BACKGROUND
2.1 IT Service Management
Due to the popularity of shared services and
outsourcing, IT services need to evolve and must be
adapted quickly to new needs and technologies of
different organizations. Services must improve their
functionality, and fulfil the business requirements in
the least time possible and with an acceptable
estimate. This means that organizations should apply
an appropriate management of the services,
providing a business focus to enable integration
between business and IT.
There are several well established good practice
frameworks used to create an effective IT Service
Management system. Nowadays, ITIL
(http://www.itil-officialsite.com/ home/home.asp) is
the best known and most widely accepted guidance
and it has become the de facto standard for ITSM.
For sake of clarity, we select only one part of
ITIL to describe the work presented in this paper:
the Incident Management process from the Service
Operation stage. From a customer viewpoint,
Service Operation is where actual value is seen
(OGC, 2007). The Incident Management process
helps IT service providers in evaluating how
customers perceive a specific service. Also, this
process is a relatively simple one with a reasonable
number of classes and properties associated.
2.2 The Model-Driven Engineering
The emerging Model-Driven Engineering (MDE)
addresses the inability of third-generation languages
to cope with increasing software complexity,
allowing designers to describe domain concepts
effectively (Schmidt, 2006). MDE revolves around
models (defined in terms of formal meta-models),
and model transformations, which provide a
powerful mechanism for incremental and automatic
software development.
The Model-Driven Architecture (MDA)
approach (OMG, 2003), defined and supported by
the Object Management Group (OMG), defines a
particular MDE process aimed at separating the
business logic from the technological platforms.
MDA proposes three modelling layers specified as
MOF meta-models, namely (ordered from highest to
lowest levels of abstraction): CIM (Computation
Independent Models), PIM (Platform Independent
Models), and PSM (Platform Specific Models). From
a Software Engineering perspective, ontologies are
considered as descriptions of CIMs.
3 AN ONTOLOGY FOR
REPRESENTING ITIL-BASED
SERVICE MANAGEMENT
MODELS
In this section, we discuss an approach to build an
ontology-based DSL for ITSM from the ITIL Service
Management Model, aimed to take advantage of the
ontologies and the model-driven approach
capabilities. The Onto-ITIL is the representation of
the ITIL Service Management Model formalized by
means of a MOF-compliant DSL, aimed to enable
the formal creation of models, which can be
processed and transformed by means of different
modelling frameworks, such as the Eclipse
Modelling Framework (EMF).
Our approach allows organizations (IT service
providers): (1) to catalogue the best practices in
ITSM, (2) to obtain a simplified representation of
ITIL Service Lifecycle, (3) to provide a common
shared domain conceptualization of ITSM, (4) to
formally define the elements of the ITIL Service
Lifecycle and their interactions in a machine-
processable way, (5) to adopt and adapt ITIL
according to the needs of the organization, (6) to
focus in a specific process in order to implement it,
(7) to enable the separation of the meaning from the
processing and (8) to obtain a high-level
requirements model. This model can be reused to
develop the information systems that underpin IT
services by means of model transformations in the
context of MDE.
The proposed ontology is defined by adopting
the Web Ontology Language (OWL) (Smith et al.,
2004), which provides automated and efficient
reasoning facilities, together with the Semantic Web
DEFINING THE SEMANTICS OF IT SERVICE MANAGEMENT MODELS USING OWL AND SWRL
379
Rule Language (SWRL) (Horrocks et al., 2004) for
the semantic constraints and knowledge inference.
The open source Protégé-OWL tool
(http://protege.stanford.edu/) is used in this research
as an ontology editor to demonstrate the
applicability of our work. Protégé includes the
SWRLTab which is an extension for editing and
executing SWRL rules in conjunction with Jess
(http://www.jessrules.com/), a rule engine.
3.1 Onto-ITIL Principles
The IT service management model proposed in this
work is based on two concepts and two relations.
The concepts are specification and activity, and the
relations are coordination and conformance: an
activity represents the actual ITIL-based activity
carried out by an organization and is said to be
coordinated by an organization specification, and an
organization specification is said to conform to its
ITIL specification.
These principles enable us to provide a definition
of what is an IT service management model in the
Onto-ITIL context.
3.2 Onto-ITIL Ontology
In order to take advantage of existing ontologies to
create our approach for ITIL-based service
management domain, we have defined some classes
in terms of an upper ontology that is independent of
a particular domain. This allows us to relate ITIL-
based service management data to other data
expressed on the Semantic Web. In this case, we use
OpenCyc (http://www.opencyc.org), the public
version of the Cyc technology (Lenat, 1995) that
represents the most complete general knowledge
base and reasoning engine. We use the prefix “oc” to
reference the namespace of the OpenCyc ontology.
An oc:Specification is the super class for all
concrete specification types that constitute the
underlying IT service management model.
ActionTemplate, Lifecycle, Stage and Process are
examples of subclasses of oc:Specification in the
ITIL ontology. In our context, an oc:Specification
represents an abstract work that constitutes a
description of how IT services have to be managed
in order meet business user’s expectations.
An ActionTemplate represents the different kinds
of actions for describing the activities designed to
achieve a particular result. A Lifecycle represents the
various stages in the life of any IT service
management model element (IT Service,
Configuration Item, Incident, Problem, etc.). The
Lifecycle defines the categories for status and status
transitions that are permitted using the hasStage
property.
A Stage represents any phase of a Lifecycle.
Stages are composed of Processes (hasProcess
property). A Process defines the set of activities
designed to accomplish a specific objective, the
scope, risks, challenges, value to business,
technologies, and interfaces that are needed to
implement it.
Processes, Services and Activities are measured
in terms of Metrics. Metrics must be designed in line
with customer requirements for service
management. A Metric is considered as a KPI (Key
Performance Indicator) when it measures the
success with the SLAs defined with a Customer.
An oc:Action is the super class for all concrete
action types, and it is used for the workflow
dimension (process flow) of our ontology, i.e. the
Activity composed of a set of actions that are carried
out and coordinated by the specifications as part of a
business process, during which documents or
information are passed from one participant to
another, according to a set of procedural rules. All
oc:Actions are performed by an oc:IntelligentAgent,
i.e. the actor who is responsible for. The Opencyc
concept oc:PurposefulAction is the subclass of
oc:Action. An oc:PurposefulAction represents the
actions that are consciously, volitionally, and
purposefully performed by at least one agent.
An ITService is a service provided to one or
more Customers by an ITServiceProvider. An
ITService represents the means of delivering value to
Customers by facilitating outcomes.
To control roles, we use the oc:IntelligentAgent
class. SuperUser and oc:Organization are examples
of subclasses of oc:IntelligentAgent.
An ITServiceProvider is a service that provides
ITServices to internal or external Customers. A Shift
is a group or team of people who carry out a specific
role for a fixed period of time. A SupportGroup is a
group of people with technical skills.
Each oc:IntelligentAgent may have several roles
(RoleRelation class). A Role represents a set of
Responsibilities granted to a person or team that
takes part in an oc:PurposefulAction. One Role may
have multiple responsibilities, which are defined
according to the RACI matrix in ITIL V3. Specific
roles and responsibilities are defined for each
oc:IntelligentAgent in an oc:PurposefulAction using
the hasRoleRelation, hasRoleType, hasRACICode
and roleValue properties.
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4 MODELING CONSTRAINTS
AND ADDITIONAL
KNOWLEDGE WITH RULES
In our approach, we use SWRL for consistency
checking, model validation, business rules analysis,
etc. Rules defined in SWRL are combined with an
OWL ontology providing all the relevant aspects of
the ITIL specification and improving the
management of IT services.
In order to test our approach with regard to
reasoning capabilities, these rules are executed in
Protégé using the Jess rule engine. This enables us to
verify constraints and inconsistencies in the IT
service management model, and incorporate new
knowledge into the model to better management of
IT services. We consider two types of rules: service
management consistency and organization rules.
Service Management consistency represents rules
that are related to all instances of Onto-ITIL models.
Organization rules represent rules that are
specific to organizations. Organization rules are part
of an organization specification.
5 CONCLUSIONS
In this paper, we show how ITSM models,
formalized by means of an ontology-based DSL,
may help organizations adopt and adapt best
practices in ITSM in a well-defined manner for
business success. Our work captures the knowledge
of best practice guidance in ITSM, including the
workflow specifications and the rest of ITIL-based
IT service management model elements, such as
metrics and formal documents.
The Onto-ITIL principles separate the ITIL
specification part from the organization specification
part of an IT service management model in order to
manage their evolution and coordinate the actual
ITIL-based activities associated to all the
organizations specifications.
One of the main benefits of our approach is that
we can define the semantics and constraints
associated to IT service management models
avoiding ambiguities. These semantics-enriched
specifications are defined just in terms of the IT
service management domain, independent of any
software consideration. Also, the resulting software-
independent models, defined by means of OWL, can
be transformed into formal models that are fully in
accordance with MOF. These models describe the
high-level requirements (i.e., the ontology
engineering part) of the ITIL-based information
systems that underpin the IT services.
OWL and SWRL are used to represent our
proposed ontology and the underlying constraints,
and the Protégé tool is used to test the approach. We
have grouped the SWRL rules into two different
categories that will be used as the basis for defining
service management rules. The combination of
ontology-based and rule-based reasoning capabilities
is used: (1) to validate the ITIL Service management
model (service management consistency) and (2) to
manage ITIL-based organization specifications
(organization rules). To the best of our knowledge,
such a formal ITIL Service V3 Management Model
definition has not been proposed for the existing
ontologies in ITSM.
Future work of this proposal includes: (1) to
complete the definition of the proposed ontology and
the underlying constraints for ITIL-based IT service
management, and (2) to implement a (semi-
)automated model transformation from Onto-ITIL-
based high-level requirements models to system
models that provide lower level requirements
models by means of a M2M transformations using
the ATL (Atlas Transformation Language)
(http://www.eclipse.org/m2m/atl/) or the QVT
(Query/View/Transformation) (OMG, 2008)
specifications.
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