Managing enterprise applications as dynamic resources in corporate semantic webs: an application scenario for semantic web services.Position paper for the W3C
Workshop on Frameworks for Semantics in Web Service, June 9-10, 2005
Fabien Gandon, Moussa Lo,
Olivier Corby, Rose Dieng-Kuntz
INRIA, ACACIA Lab., 2004 rt des Lucioles, BP93, 06902 Sophia Antipolis Fabien.Gandon@sophia.inria.fr 1. Corporate semantic websSemantically annotated
information worlds are, in the actual state of the art, an effective
way to make information systems smarter. If a corporate memory becomes
an annotated world, corporate applications can use the semantics of the
annotations and through inferences help the users use the corporate
memory.
The ACACIA team at INRIA focuses on knowledge management solutions based on semantic Web technologies. As shown by the insert on the right [3], we use RDF Model, RDF Schema and OWL (essentially OWL Lite) to describe ontologies and implement knowledge models. Organizational entities and people are annotated in RDF and its XML syntax is used to store and exchange the annotations. This choice enables us to base our system on the W3C recommendations that benefit from all the web-based technologies for networking, display and navigation. This clearly is an asset for the integration to a corporate intranet environment that often relies on web technologies. Relying on W3C standards also enables us to integrate access to external sources in the corporate memory (e.g. digital libraries offering references in the application domain), interconnect parts of intranets to form extranets, generate focused portals for customized access (e.g. to address device independence, mobile access, etc.), etc. Clearly relying on open standards is important for effective knowledge representation and knowledge management solutions. Our work resulted in the development of a semantic Web search engine (Corese [1]) enabling us to analyze, query and infer from descriptions in RDF(S)/OWL. CORESE implements a query language close to SPARQL [20] and a production rule language used to declare domain-dependent inference rules. Corese was tested with a variety of schemas such as the Gene ontology (13700 concept types). It also provides approximate search capabilities (vital to information retrieval systems) and comes with a semantic web server providing presentation capabilities to dynamically generate query interfaces and templates to render results.
We can summarize our approach
in three stages:
Among the domain applications
where we implemented corporate semantic webs and used Corese are:
2. Corporate application managementUntil the end of the 90's,
enterprise modeling has been mainly used as a tool for enterprise
engineering. But the new trends and the shift in the market rules led
enterprises to become aware of the value of their memory and of the
fact that enterprise model has a role to play in knowledge management
too. Just like data-integration problem can benefit from
corporate-level models, technology and application integration problem
can benefit from these same models, and this was recognized by
practitioners of Enterprise Application Integration.
"Organizations that are able to integrate their applications and data
sources have a distinct competitive advantage: strategic utilization of
company data and technology for greater efficiency and profit. But IT
managers attempting integration face daunting challenges ― disparate
legacy systems; a hodgepodge of hardware, operating systems, and
networking technology; proprietary packaged applications; and more.
Enterprise Application Integration (EAI) offers a solution to this
increasingly urgent business need. It encompasses technologies that
enable business processes and data to speak to one another across
applications, integrating many individual systems into a seamless
whole." [9]
More and more often, the ACACIA team must face scenarios requiring not only knowledge access but also computation, decision, routing, transformation, etc. Until now, our corporate semantic webs focused on providing a unified and integrated access to a range of knowledge sources; but there is a growing demand to get the same facility to access corporate applications and services and to integrate both worlds. Users expect IT managers to get very different computing systems (desktops, mobile phone, PDA, mainframes, etc.) to talk together and, even worth, to get the variety of applications that run on them to talk together. But what does it mean to talk together? Who talks to whom? What are the flows and processes? What are the purposes? Users don't only want to get access to the needed pieces of information, they want it in a format they are used to, with some certification of quality or of provenance, with appropriate tools to analyze it, modify it, etc. Usage scenarios are moving from a unified access to information to a unified access to information and applications. Corporate memories not only include information mediums but more generally:
All these services may be
internal or external to the company yet users want them to interoperate
smoothly and, even better, to automatically integrate their workflows
at the business layer.
3. Corporate semantic web servicesIn the CoMMA [3] project we
experienced with multi-agent architecture to provide distributed
software architecture managing distributed memories. Societies of
agents were dedicated to the management of the annotations and the
ontology. We designed protocols sustaining the social structures of
these groups of agents, in particular techniques for intelligently
distributing annotations in the existing archives and for decomposing
and routing queries to solve. This was our first experience with
non-client-server distributed software architecture for a corporate
semantic web and the association between distributed formal knowledge
(semantic web) and distributed artificial intelligence (agents) proved
to provide a very powerful paradigm for corporate memory management. [3]
Clearly, the evolution of web services towards semantic web services proposes an alternative to agent architectures and we are naturally investigating the extension of the Corese semantic Web Server to a distributed web platform relying on web services to deploy a flexible distributed software architecture that can match intranets structures. In the myCampus project [4] we experimented with a context-aware environment aimed at enhancing everyday campus life at Carnegie Mellon University (CMU). The environment revolves around a growing collection of task-specific online services (e.g. restaurant concierge, message filtering agent, etc.) capable of automatically accessing a variety of contextual information about their users. We introduced a Semantic Web architecture aimed at enabling the automated discovery and access of personal resources in support of a variety of context-aware applications. Within this architecture, each source of contextual information (e.g. a calendar, location tracking functionality, collections of relevant user preferences, organizational databases) is represented as a Web service. An e-Wallet acts as a directory of contextual resources for a given user, while enforcing her privacy preferences. Web services are a standardized way of integrating Web-based applications using open standards over an Internet protocol backbone:
Web services allow
organizations to make public a programmatic access to one of their
application without exposing the internal architecture of their IT
systems. However, compared to agent-based platforms we used before,
these technologies had the disadvantage to remain at the syntactic
level while all the resources we manipulate are described in
ontology-based models enabling us to leverage the semantics of
descriptions in inferences.
In the corporate memories we developed so far, the annotations generally describe documentary resources or corporate structures, but, when relying on schemata as the ones advocated in OWL-S [10], these annotations can describe web services available online (intranet, extranet, Internet). This means that Corese allows us to automate the identification of web services available to a user. Following a service-oriented architecture and a find-bind-execute schema [11] Corese nicely fits in the picture with semantic web services: In this new architecture, we moved:
Our current implementation is
embedded in the semantic web server architecture and works in three
steps: (1) we provide automatic discovery of web services using Corese
queries upon their OWL-S annotations just as for other resources of the
corporate memory; (2) when a service is selected by a user, instead of
displaying the resource as it is the case for documents for instance,
we dynamically generate a form from the grounding and the process
providing an interface to call the service; (3) on submitting the form,
the inputs are used to generate a dynamic client and the call to the
web services. The output is then simply displayed as a web page.
This simple architecture already enables us to provide dynamic invocation of services without any prior knowledge of its description: Corese queries allow us to get the necessary information about a service from the knowledge base of service descriptions in order to dynamically invoke it. Here, in the corporate memory, Corese provides the equivalent of a corporate semantic UDDI registry. The screenshot in Figure 1 shows two windows: (1) a window in the background corresponding to the generic search interface of Corese. It shows the result of a query where some services were found. One of them is the service "post" which provides an access to our ldap directory. The user selected this service and obtained (2) a window providing a form to specify the inputs of the service (here the name of an employee). Once submitted, this form triggers a call to the web service which is then dynamically executed and provides outputs displayed in the web interface (here the phone number of the employee). Figure
1: an example of discovering a corporate web service with Corese and
dynamically invoking it. 4. Perspectives and future workWe are looking at several open
issues and perspectives and especially two of them in the short term:
These two first issues mean we
are looking for a standardization of the works including: composite
processes in OWL-S, WSFL (Web Services Flow Language), WSCI (Web
Service Choreography Interface), WSCL (Web Services Conversation
Language), XLANG (Microsoft BizTalk), WSMF (Web Services Management
Framework), BPEL4WS (Business Process Execution Language for Web
Services). Composition and choreography issues currently are the most
symptomatic examples of the need for a standardization consortium to
take the lead, and W3C definitively is the best candidate. We are
witnessing a multiplication of contributions for each and every stage
of the life-cycles of web-services and especially discovery and binding
[12][13][14][15][19] and discovery and composition [7][16][17][18].
There is clearly a need to homogenize the different approaches before
the differences hamper the foundations of Semantic Web Services such as
interoperability.
In addition, our involvement in the semantic web deployment and our participation in the W3C working group on Semantic Web Best Practices mean we also are interested in:
References[1] Corby, O.,
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CORESE search engine. In Proc. of the 16th European Conference on
Artificial Intelligence (ECAI'2004), Valencia, 22-27 August 2004, IOS
Press, p. 705-709
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