Information resources available as an online service within Intranet. The decision- making is not only guided by the information provided by DES but rather than the Web technology, the process is entirely based on communication between ISP Agents and Web agent. While negotiating compromises for conflict solving to share common resources, decision centers use Web service to conduct various complementary tasks. To illustrate the idea, a simple case study is given. Keywords: Decision Support System (DES), Integrated Station of Production (ISP), Software agents, Web-based DES. 1 Introduction
Computer technology progress has led to widespread use of computerized support in various activities. Particularly, traditional decision support systems (DES) focus on computerized support for making decision with respect to managerial problems. There Is an emerging and fast growing interest In computerized support systems In many other domains such as information retrieval support systems, research support systems, teaching and learning support systems, computerized medical support systems, knowledge management support systems, and many more. The recent development of the Web generates further momentum to the design and
Implementation of support systems. Obviously enough, there is a strong trend for studying computerized support systems especially on Web platforms. Research on information retrieval support systems, research support systems, teaching and learning support systems, decision support systems, computerized medical support systems, and knowledge management support systems are Just some of their representatives. This paper will focus on one of the important research topics of Web- based DES and online service within an Intranet. The organization of this paper is as follows.
We introduce the concept of Decision Support System and Web-based support systems in the next section. Section 3 discusses issues of recent research in Web-based decision support. In section 4 we propose our contribution. In section 5 we explain our proposed model. Section 6 shows a sample application for the Web-based DES. Finally, a conclusion and future work are given in Section 7. 2 Decision Support System and Web Based Decision Support System 2. 1 Decision Support System Before we start with detailed aspects of the issue, it is important to tackle the definition of decision support systems.
Decision Support Systems can be defined as computer technology solutions that can be used to support complex decision making and problem solving (see Shim et al. ). To account decision problems complexity and uncertainty, we understand the DES as a set of computer-based tools that provide decision maker with interactive capabilities. It aims to enhance his understanding and information basis about considered decision problem through usage of models and data processing. The latter, in turn, allows reaching decisions by combining personal Judgment with information provided by these tools.
The classic DES tool design is comprised of the components for: ; Database management capabilities with access to internal and external data, information and knowledge; ; Powerful modeling functions accessed by a model management system; and ; User interfaces that enable interactive communication between the user and system. Decision Support Systems (Adds) are interactive computer-based systems intended to help decision makers utilize data and models to identify and solve problems and make decisions. The "system must aid a decision maker in solving nonprogrammer, unstructured (or 'semiconductors') problems... E system must possess an interactive query facility, with a query language that ... Is ... Easy to learn and use" . Adds help managers/decision makers use and manipulate data, apply checklists and heuristics, and build and use mathematical models. According to Turban , a DES has four major characteristics: it incorporates both data and models; it is designed to assist managers in their decision processes in semiconductors (or unstructured) tasks; it supports, rather than replaces, managerial judgment; and its objective is to improve the effectiveness of decisions, not the efficiency with which decisions are being made.
According to , decision support systems fall into five categories: Communications- Driven DES - uses network and communications technologies to facilitate collaboration and communication; Data-Driven DES - emphasizes access to and manipulation of a time-series of internal company data and sometimes external data; provide complete document retrieval and analysis; Knowledge-Driven - intended to suggest or recommend actions to managers. These Adds are personal computer systems with specialized provisioning expertise; Model-Driven DES or Model-oriented DES - emphasizes access to and manipulation f a model, e. . Statistical, financial, optimization and/or simulation. Simple statistical and analytical tools provide the most elementary level of functionality. 2. 2 Web-based Decision Support System Web used technologies are employed to improve the capacity of decision support systems through decision models, On-line Analysis Processing (OLAP) and data mining tools that allow "standardized" publishing and sharing of decision resources on the Internet.
In a web-based decision support system, all decision support related operations are performed on a network server n order to benefit from platform independence, shorter learning curves for already familiar users with the Web tools and web navigation, lower software distribution costs, ease of performing system updates and "risibility' of decision modules and information on the Internet through standardized protocols and formats .
According to , the importance of using Web-based DES originates from the growing amount of available information that should be identified, controlled and accessed remotely using web based tools to support risibility of integrated decision modules. Using such systems, an enterprise can create survey software, Web based arms, build document-driven DES for requests and approvals. They help global enterprises manage and improve decision processes through improved efficiency, better process control, improved customer service, more flexible re-design, and streamlining and simplification of business processes.
Using Web-based DES, decision-makers can share open decision modules on the Internet using standardized protocols such as HTTP, and a standardized format like XML or DAML. According to , Web-based systems are regarded as В«platforms of choice" for delivering decision support while taking into account many technical, economic and social considerations. The migration towards web based DES denotes a shift from DES generators (that allow users to develop specific applications characterized by limited deployment, inflexibility) to integrated cross application orientations that emphasize the reuse of applications and components.
By deploying Web capabilities, multiple knowledge bases and knowledge processing techniques can be used. The design of decision support systems has been affected by the availability of a wide range of web based tools, techniques and technologies. The use of web tools are reshaping the description of relations between information components and decision oodles in a way that affects both the physical and logical design of the DES, model visualization, curability of decision modules and the development life cycle of DES.
As a result, the underlying architecture for Web-based DES has moved from mainframes, to client-server systems, to Web and network technology based distributed systems that enable the integration of large amounts of data and decisions support tools originating from heterogeneous multidisciplinary sources for provision of value-added information using knowledge discovery and data mining tools. 3 Recent research in Web-based Decision Support System This section reviews and summarizes the state of Web-based DES research in two areas: (a) architectures and technologies and (b) applications and implementations.
A number of articles have reviewed more specific topics related to Web-based DES. For example, Skulks and Paul  reviewed Web-based simulation and Kerosene and Normal  reviewed Webbed negotiation support. 3. 1 Architectures and technologies A number of articles discuss architectural issues, frameworks, usability, and other technology topics that are generally applicable to Web-based DES. Gregg et al.  plopped a DES metadata model for distributing decision support systems on the Web.
Bahrain and Chuddar  conducted an empirical study to investigate customers' satisfaction with a Web-based decision support system. Lyre et al.  studied model management for decision support in a computing environment where enterprise data and models are distributed. Gunter et al.  proposed Structured Service Models that use a variant of structured modeling. This proposed approach can help users find information resources available as an online service within Intranet. Ghana and Goddard  applied Software Architectures to the design of
Web-based DES. Miter and Valence [1 3] provided an overview of Webbed optimization for model-driven decision support, discussed two paradigms (ASP and e- Services), and articulated technology issues for an e-Services model. 3. 2 Applications and implementations Many researchers and vendors have reported Web based DES case studies and the development of prototype applications. Kohl et al. [1 1] reported a case study of a Web-based DES for hospital management called Physician Profiling System (UPS).
Angina and Watt  developed and implemented a Web-based DES that used a model eased on fuzzy set theory to perform risk analysis for e-commerce development. Dong et al.  developed a Web-based DES framework for portfolio selection. Cassandra  identified key issues in managing service contracts and developed a prototype that can support a manager's planning process. Ray [1 5] reported a case study that demonstrates the implementation of Web-based decision support technologies. Delve et al. 3] developed a Web-based DES, called Movie Forecast Guru, to help decision makers in the movie industry. There are many additional case studies related to deploying Web-based decision support systems. For example, Summary and Meyer  report the development of a Spatial DES prototype for the City of Columbia, Missouri. 4 Contribution Given the multidisciplinary data sources and related decision support tools, the design, specification, and implementation of a Web-based DES often in a distributed environment is still an open research problem .
Firstly, a Web-based DES often Those data and related tools originally are not designed to work together. Traditional DES design methods lack the ability to help organize them in a hierarchical view and specify the software architectures of a Web-based DES in a formal way. Secondly, with the assistance of Web and network technology, the data and decision support tools from multidisciplinary areas can be located on computers distributed over a network. In such a distributed environment, a Web-based DES needs a distributed framework to manage and integrate the data and tools in a seamless way.
Furthermore, the work reported in  concerns a novel approach for decision making. In her paper, she addressed an agent architecture-based model in order to present a multicultural DES which can be applied to solve some uncertainty problems in dynamic production system scheduling. The established negotiation contract thus deals with certain exceptions; it is based on the agent approach. The major advantage with this modeling paradigm consists in facilitating access to the executed tasks carried out by Integrated Stations of Production (ISP) agents.
This paper proposes an agent-based Web DES, its principle is to help users solve the problems of failure of their resources in an industrial estate on a web service using online within an intranet. In addition to the Web Service in our contribution we will use negotiation between ISP Agent and other agents on the web (Fig. ). The ISP Agent will check the resources of a workshop at the resource failure, it will contact the agents based Web that will help for decision making to resolve the failure. To illustrate the feasibility of the idea, an MAUL diagram is given in Fig. . Enterprise 1 Enterprise 2 web Site 1 web Site 2 Web Site n Web Service 1 Enterprise n Web-based DES Resource Agent Proposal Agent Analyzer Agent TГchew 1 Resource 2 Workshop Fig. L . General architecture 5 Scenario for Proposed Model An Analyzer Agent Analyze and filter The breakdown A Resource Agent A Proposal Agent Seek the reference of the resource broken down Research Found reference x Not found reference Seek the solution of the breakdown Found solution Not found solution Repair the breakdown Order the resource Accept the order Resource ordered Fig. 2.
Communication between Agents (Diagram of Sequence) 5. 1 The Analyzer Agent Structure The analyzer agent includes several types of functional modules such as: analysis module, proposal generator module, a database, a knowledge base, rules base, a filter and an interface. The analysis module is the core of this architecture; its role is o use the data input which is stored in database, knowledge which is stored in knowledge base and the rules which are stored in rules base. This is to analyze and filter the breakdowns, and produce like exit a generator of proposal of analyzed and filtered breakdowns.
The interface module manages the information exchanges between the agent analyzer and the other agents. During the problem resolution, the analyzer agent will require the resource agent to seek the resource reference on the Web. Database Interface Module Knowledge Base Analysis Module Rules Base Filter Proposals Generator Module Fig. 3. The analyzer agent structure 5. 2 The proposal agent structure After having to find the reference of the resource broken down on the Web, the agent analyzer will require the proposal agent (see Fig. ) to launch an advanced research on the Web concerning the breakdown envisaged for this resource. The proposal agent includes several types of functional modules such as: research module, solutions generator module, a data base, a knowledge base, rules base, web data launching an advanced research on the Web (in the Web Database) as for the breakdown of the resource. At this time there, it will generate several solutions. The interface module manages the information exchanges between the agent proposal and the other agents. Web data Research Module Solutions Generator Module Fig. . The proposal agent structure 6 Sample Application for the Web-DES We use the resource allocation problem to demonstrate how the agents solve problems by interactions among agents. A company wishes to produce a special computer installation with its own hardware and software for a customer. The following print screens given in both (Fig. 5) and (Fig. 6) show a practical situation when decision-making is necessary. Fig. 5. Simulation Function Fig. 6. Simulation of a Breakdown in the Resource 7 Conclusion A Web-based DES uses the Web as a portal to the underlying DES.
It lets interested users access and make use of the underlying DES through the Web. Moreover, we believe a distributed implementation of the underlying DES is also important for a Web-based DES presents a challenge, which needs the combination of a DES with distributed computing technology. Our proposed multi-agent approach provides a practical way to implement a Web-based DES. More precisely, we have integrated agents into Web-based DES for the purpose of automating more tasks for the decision maker, enabling more indirect management, and requiring less direct manipulation of the DES.
In particular, agents were used to solutions found to be significant. Based on this, and considering that communication capabilities play an essential role in Web-based DES to enable 'any-time, any-place" operation mode of the system. Further work based on coordination protocols between agents needs to be done. Particularly, the context information domain included in the software tool will be extended in order to improve the support for decision making and the coordination activities. The proposed architecture of the Web-based DES is under development.