and composition, motivated the proposal of different
approaches for the definition of what was baptized
as the Semantic Web Services. OWL-S (Semantic
Markup for Web Services), for instance, combines a
set of inter-related OWL ontologies that define terms
used in service-oriented applications. Besides OWL-
S (adopted in the work described in this paper) two
other proposals already play an important role in the
Semantic Web Services scenario: the WSMO (Web
Services Modeling Ontology) (W3C, 2005)) and the
SA-WSDL (Semantic Annotations for WSDL and
XML Schema) (W3C, 2007), recently adopted as a
W3C recommendation.
Techniques which enable markup and automated
reasoning technology to describe, simulate, test, and
verify compositions of Web services are discussed in
(Narayanan and McIlraith, 2002). The authors define
the semantics for a relevant subset of OWL-S in terms
of a first-order logical language (Situation Calculus).
With the semantics in hand, service descriptions are
encoded in a Petri Net formalism. The implemented
system is able to read in OWL-S service descriptions
and perform simulation, enactment and analysis. The
use of advanced workflow and activity concepts in the
composition of Web services is the proposal of (Fileto
et al., 2003). The approach is called POESIA (Pro-
cesses for Open-Ended Systems for Information Anal-
ysis), an open environment for developing Web appli-
cations using metadata and ontologies to describe data
processing patterns developed by domain experts. It
supports Web service composition using domain on-
tologies with multiple dimensions (e.g., space, time,
and object description).
The electronic Government (e-Government) do-
main includes the ”set of all processes which serve
decision-making and services in politics, government
and administration and which use information and
communication technologies” (KBSt, 2006). Re-
cently a new approach to e-Government is gaining
momentum: the citizen-centric government, where
citizens and businesses are considered customers of
the public administration, so that their needs come
first, rather than bureaucracy or other imperatives in-
side the government machine (GOV3, 2006). In this
context, usually a government-wide service-oriented
architecture is applied to develop a single place that
offers access to all government informational and
transactional services. Several research efforts in the
e-Government domain can be found in the literature.
For instance, a system which automatically generates
Web services customized to citizens’ needs and also
to government laws and regulations is presented in
(Medjahed and Bouguettaya, 2005). It proposes three
levels of service customization: the Citizen level, the
Service level and the User interface level. A meta-
data ontology, used to describe e-Government ser-
vices and operations, is also introduced. An approach
for the semi-automated design of data flows between
Web Services that are semantically described using
different ontologies and data representations is intro-
duced in (Barnickel et al., 2006), including a rule-
based mechanism for user-transparent mediation be-
tween ontologies spanning multiple application do-
mains.
3 ENABLING TRANSPARENCY
As already mentioned, transparency is becoming a
fundamental requirement in citizen-oriented applica-
tions. One of the possible strategies to improve trans-
parency is to guarantee traceability at the service
level. Traceability is defined by the International
Organization for Standardization (ISO, 1994) as the
”ability to trace the history, application or location
of an entity by means of recorded identification”. We
introduce a strategy based on traceability policies to
regulate the execution monitoring of composite e-
Government services and detail it next.
3.1 The Middleware
The strategy presented in this paper is modeled and
implemented over an e-Government service middle-
ware called CoGPlat (Citizen-oriented e-Government
Platform) (Santos et al., 2005). Its main goal is to
support applications that enable the interaction and
collaboration among governmental entities, organiza-
tions and citizens and its infrastructure includes (see
Figure 1): a Service Bus, an interface between the
middleware services and the applications; four core
facilities (described next); a Service Discovery and
Execution Layer, responsible for selecting the Se-
mantic Web Services to participate in the compo-
sitions and also for interacting with those services
at process run-time; and a set of Support Services
which provides security, persistence, reliable messag-
ing and transaction support to the processes running
over the platform.
The four middleware core facilities are (see also
Figure 1): the Transparent Services Center, respon-
sible for dynamically building the service composi-
tions according to the application requests; the Meta-
model Management Center, which offers services
and tools to manage the models, metamodels and on-
tologies used in the description of services, composi-
tions, processes and entities; the E-Governance and
E-Democracy Center, which delivers generic ser-
TRANSPARENCY IN CITIZEN-CENTRIC SERVICES - A Traceability-based Approach on the Semantic Web
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