Using mobile agents to solve the distributed buying problem.

A mobile agent system was then designed and implemented to serve as a proof-of-concept system for an agent-based solution to the problem. Where other people's work has been used, it has been duly acknowledged in the text.

Objective

Our prototype system allows buyers in a factory to delegate to agents the task of communicating with suppliers and factories about quotes and orders. The automation of these processes by the system of mobile agents helps to optimize the buyer's time and reduce costs for the enterprise, especially through the unnecessary purchase of materials available in other plants, thus solving the problem.

Thesis Outline

The chapter concludes by discussing how mobile agents can be used to reengineer procurement at Billiton. The overall design of the mobile agent system as well as the role of each agent in the system is presented here.

Introduction

Towards a Definition

Some Example Definitions

This is because if an agent is to function adequately in a dynamic environment, it will need some degree of AI. 34;An agent is anything that can be seen as perceiving its environment through sensors and acting on this environment through effectors.

The Stereoscopic View

A precise theory of the particular mental category; the theory must have clear semantics, and should correspond to the common use of the term;. The second view, or agents by description, is basically the same as deciding whether something is an agent using the two concepts of agency: examine the behavior and properties of the entity in question, see if it matches some authoritative description by an agent, and then proclaim it as an agent or not.

A Working Definition

A Taxonomy of Agents

Hybrid agents: Hybrid agents are agents that are a combination of the two types previously mentioned. According to the typology, it is an ideal agent that does not yet exist (hence it is shaded in figure 2).

Introduction

The Mobile Agent Paradigm

The code-on-demand paradigm gives the client the requested resource and processing power. This means that the client does not require pre-installed code - the service knowledge is downloaded from the server and processed when needed.

Figure 3 - Client-Server Paradigm [Lange & Oshima, 1998]

Standardization and Agent Frameworks

The MASIF Standard

The combination of agent system type, language, and serialization method refers to the profile of an agent. To initiate a transfer, an agent makes an API (Application Programmer Interface) call to the source agent system.

Figure 6 - The MASIF architecture (Adapted from [MASIF98, page 10])

The FIPA Standard

The AP consists of the machine(s), the operating system, the agent support software, the FIPA agent management components (Directory Facilitator, Agent Management System, and Message Transport Service), and agents. The first method involves the agent on the local AP sending a message to the local MTS. The third method is a direct communication from the local agent to the remote agent without using MTS.

Formal Software Models for Mobile Agents

Advantages of Mobile Agents

Asynchronous and autonomous execution: Mobile agents can work effectively in networks where connections are frequently broken. Mobile agents avoid this problem by migrating to each host and establishing a communication channel between them. Most mobile agents are built with languages, such as Java, that are host independent [Butte, 2002].

Introduction

Aglets

Fundamental Aglet Operations

Dispatch: Calling the dispatch method of an aglet's proxy object sends the aglet from its current context to the destination context. Activation and Deactivation: The deactivate method of an aglet's proxy object causes the aglet to stop its thread of execution and save its state to secondary storage. Disposal: Calling the disposal method of an aglet proxy object results in the aglet being removed from the context and garbage collected.

Aglet Security

In case agents are in the same container, the message is passed as an event. If agents are on the same agent platform but on different hosts, the message is passed through RMI. If agents are on different agent platforms, the message is sent using the Internet Inter-ORB Protocol (HOP).

Figure 13 - The JADE Agent Platform [Bellifemine et al., 2002]

Hive

Introduction

Non-Agent-Based Electronic Commerce

Enterprise Resource Planning Systems

ERP systems evolved from material requirements planning (MRP) and MRP 11 systems, which were first used in the 1960s and 1980s, respectively. MRP systems are defined as legacy systems that enable companies to anticipate, track and manage all components or complex manufactured goods [Laudon & Guercio, 2002]. MRP, MRP 11 and ERP systems have traditionally not dealt with e-commerce as we defined it - they were more focused on improving efficiency within the company rather than on interactions with entities outside the company [Moodley, 2001]. this is the reason MRP systems are discussed here rather than in the previous section on traditional e-commerce).

Agent-based Electronic Commerce

Classification Schemes for Agents in Electronic Commerce
The Delegate, Market, Business Model Scheme
The Purchasing Life Cycle Scheme
Papazoglou's Typology
Agent-based Auction Systems

In the business-to-business domain, where business models such as electronic exchanges are more appropriate, agents such as AgentWare's Syndicator (it enables business-to-business electronic exchanges) can be used [Turban et al., 2002]. Negotiation: Negotiation takes place between the buyer and the selected dealer in the commercial mediation stage. The ADEPT system was used by British Telecommunications in the business-to-business domain to automatically generate network design quotes [Faratin et al., 1998].

Figure 15 - Papazoglou's Typology [Papazoglou, 2001]

Introduction

The Role of the Buyer

Types of Buying and Materials

Spot purchasing refers to purchasing materials at a market price that is dynamically determined by supply and demand [Tulband, 2002]. Please note that spot purchasing does not imply purchasing from suppliers that do not have contracts with the company. Their use is planned, they are usually not shelf items and they are purchased in large quantities through strategic purchases [Tulband, 2002].

Traditional Buying Methods

Strategic purchasing, on the other hand, involves purchasing materials at a price arrived at through a negotiated, long-term contract [Turban, 2002]. Direct materials are usually purchased from suppliers with whom the company has an established relationship [Essmeyer, 2000]. Indirect materials, also called MROs, are used for maintenance, repairs and operations, and all other items not directly used in production [Laudon & Guercio, 2002] [Turban, 2002].

Procurement Reengineering

Turban [2002] lists a number of sub-goals that can contribute to the overall goal of efficient buying. This saves the buyer time and limits the introduction of human error in the process. The flow of information between the buyer and supplier is also made faster, as electronic documents can be transferred more quickly and managed more easily than their paper equivalents (this is the basis of EDI and workflow systems).

The Buying Process at Billiton

Many different types of e-commerce systems and models have been used by companies that have attempted to use IT to reengineer procurement.

Solving the Distributed Buying Problem with Agents

Overview

The design can be viewed from an enterprise-wide perspective, showing how the system works with other factories and suppliers (Figure 17). Apart from the Supplier Agents, the Supplier Agent System functions independently of the agent system presented here. The only thing that is relevant to our design is that there is a Supplier Agent that is negotiated with and that there is a user, an employee of the supplier, who provides feedback to this agent.

The Agents and their Roles

The user agent provides the system with a graphical user interface (OUI) for the user and serves as the user's main point of interaction with the system. To send a buyer broker, the user broker sends a request to the interface broker. It is created and sent by the buyer's agent to the suppliers listed in the shipment request.

Discussion

This chapter describes the implementation of a mobile agent system for the Hillside plant based on the design presented in the previous chapter.

Hardware and Software Used

Databases and the System Dataflow

The Database Tables

The order number is a unique identifier for each order and is therefore the primary key for the table. DispatchCondition Indicates whether the purchasing agent dispatched for the order has returned or not, and what the current negotiation round is for the order. Reference is made to Table 3 for the SUPPLIER and MATERIAL tables in the plant database that describe all relevant information about plant suppliers and materials.

Table 3 - The ORDERS table in the user database

System Dataflow

The materials and their suppliers are chosen by the user depending on what his user group has access to in the database. The quantity, price per item and total cost of an order are determined by the user. The date of an order (OrderDateTime), the identity of the user (Controller) and the user group (MRP Group) are automatically provided by the User Agent, as these are initialization parameters for the User Agent.

The Order and Quote Life Cycle

The order number for each new order is generated using a stored procedure in the database. The order status and shipping condition have default values in the database at the time of creation. A change is made to the order status to indicate that the quote has been accepted and an order has been placed with the supplier.

Implementation of the Agents

Efficiency Issues

User agent performance is thus governed by: the speed of the DBMS; the load on the database agent; its efficiency in processing requests; and the network delay between the two agents. The size of the system developed here did not justify the added complexity of handling multi-threaded database access. This was not done as it would have tied the implementation of the agent system to a specific DBMS (stored procedures are written in procedural SQL, which can be DBMS specific).

Configuring the Tahiti Servers

User Registration and Policy Files

The 'export user' function writes the user information to an '.id' file which must be copied to the file system of the Tahiti server where it will be imported. An abbreviated form of the policy file used for the Tahiti server running on the Windows NT host is presented here. In a larger system, one solution to the problem may be to have default policy files for each of the different operating systems in use.

Future Work

34; An Intelligent Agent-Based and Virtually Default-Free Verification System: The SafeCheck System." International Journal of Electronic Commerce 4(3). 34; Buying and Selling Agents: Reshaping Commerce as We Know It." Communications of the ACM (March 1999). A Review of Legal Aspects of the Use of Intelligent Software Systems.” Computer Law and Security Report 17(2).