TOWARDS AN AGENT FRAMEWORK FOR A PASSENGER

TRANSPORTATION VIRTUAL ENTERPRISE

Claudio Cubillos and Daniel Cabrera

Escuela de Ingeniería Informática, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2241, Valparaíso, Chile

Keywords: AOSE, Virtual Enterprise, Agent Framework, PASSI.

Abstract: This work presents the first approach for obtaining a framework based on the agent technology for the

passenger transportation problem, considering a virtual enterprise domain. The agent architecture obtained

provides a baseline for the integration between end-users of the transport service and multiple transport

operators affiliated to a virtual enterprise, which provides flexibility in the incorporation and leaving of

transport operators. The participation of governmental organizations and active destinations within the

system allows the virtual enterprise having additional information on potencial opportunities of business and

assures to the users of the transport system a wider and more complete service search. The PASSI

methodology has been used as base modelling methodology for leveraging the multiagent architecture.

1 INTRODUCTION

Passenger transportation in urban areas constitutes

an increasingly important problem in our society.

Geographical coverage problems among transport

operators services, difference in the volume and

quality of handled information, among other, gives

origin to problems that range from wrong

evaluations comming from state-regulatory entities,

up to direct problems with the system final users,

which definitively results in a poor quality of

service. Therefore, the existence of a group of

transport operators, partial or totally disconnected

among them, must move towards the conformation

of a unified transport service, sustained by a virtual

enterprise for passenger transportation.

The obtention of a software framework for the

passengers transportation problem will allow to

adapt this architecture according to concrete

required characteristics, reducing in a important way

the development cost, and not less important, while

using part of a solution that already has been used in

the past and therefore with the necessary maturity

and reliability.The framework development has been

realized based on the utilization of PASSI

(Burrafato, 2002), an agent-oriented methodology

for systems development. This work represents the

continuity of a past reseach in this transport domain

(Cubillos and Gaete, 2007), concerning the

development of an agent system for passenger

transportation for a single operator under a demand-

responsive scenario.

2 PASSENGER

TRANSPORTATION

The Intelligent Transport Systems (ITS) have been

attracting interest of the transport professionals, the

automotive industry and governments around the

world. The ITS aim at development of the road

infraestructure (for example, ways) and to integrate

them together with the persons and vehicles by

means of advanced technologies of integration, from

several research areas.

On the other hand, in the last years, the Demand

Responsive Transport Services (DRTS) have risen in

popularity for several reasons, among them, strong

incorporation of information and communications

technologies, increasing the efficiency and

diminishing the operations cost. A DRT is

understandable as a component of a long chain of

inter modal service, delivering local and

complementary mobility to other conventional

transportation alternatives, such as the bus or train.

292

Cubillos C. and Cabrera D. (2008).

TOWARDS AN AGENT FRAMEWORK FOR A PASSENGER TRANSPORTATION VIRTUAL ENTERPRISE.

In Proceedings of the Fourth International Conference on Web Information Systems and Technologies, pages 292-295

DOI: 10.5220/0001528602920295

 SciTePress

2.1 Virtual Enterprise

A virtual enterprise is a cooperation network of

legally independent companies, which quickly

constitute a whole and contribute mainly their core

competences in order to exploit a specific business

opportunity. In general terms, the life cycle of a

virtual enterprise is marked by four phases, that go

from the identification, evaluation and selection of

business opportunities, to the selection of partners

for conforming the virtual enterprise; later, a phase

of operation, where the business opportunity is

exploited and a phase associated to the end of the

virtual enterprise, with the corresponding separation

of assets.

2.2 Transport Requirements

In the DRTS, is identified a set of actors, who

interact in different ways. In general terms and by

considering any service, a normal way to understand

the term "users" is to only associate it to the "end

users", that is to say, to the people that actually use

the service. However, in a complex system like this

one of passengers transportation, there are many

other users or actors who have a direct interest in the

commercial, social and infraestructure impacts.

According to the present development, the actors

considered in a DRTS correspond to:

User. Represents the end user of the passengers

transport system. The user has the faculty to make

transport requests (with their respective conditions),

as well as to indicate any problem that may affect

him and that can has incidence in the concretion of

the requested trip.

Transport Operator. Represents a transport

company within the system. A transport operator can

correspond to a single person (who is performing the

roles of operator and driver at the same time), or can

also correspond to a company composed by multiple

vehicles (fleet of vehicles). The virtual

transportation enterprise is conformed by

heterogeneous operators.

Government Entity. Represents a government party

with regulation or control faculties, which guard

current legislation and the correct service contracts

fulfillment.

Active Destination. Represents a frequent

destination within the total of existing destinations.

An active destination can make the virtual

transportation enterprise to realize a necessity or a

business opportunity available, as well as to indicate

problems associated to the transport services offered,

such as a loss in the quality of service, or restrictions

on the operation.

Traffic Information System. Represents an

external information system which gives information

on present traffic conditions, collisions, traffic jams,

alterations due to streets repair, among others.

Virtual Enterprise Information System. Contains

a transaction system and a management system of

affiliated enterprises. The first system controls all

satisfied transportation requests and those in course

of action, including all the information of the

transport request and of the transportation service

characteristics offered through the virtual

transportation enterprise. The second system

administers the virtual enterprise lifecycle, from the

affiliation of a transport operator, to the separation

among the operators and the virtual transportation

enterprise.

Transport Operator Information System. It is

made up of a Fleet Management System and a

Solver System. The first system manages at internal

level, within the transport operator, all its fleets

and/or vehicles affiliated to the virtual transportation

enterprise. The second system optimizes the

operations of transport by means of a solver of

heuristic nature.

3 AGENT TECHNOLOGY

In the last years an emergent paradigm has been

increasingly consolidating incide diverse study areas

related to the Artificial Intelligence filed. It

corresponds to the Agent paradigm, which

approaches the development of entities that could act

in an autonomous and reasoned way. Considering

that consensus does not exist on a single definition

for the term Agent, such term will be understood

according to what described in (Weiss, 1999): “An

agent is a computer system that is situated in some

environment, and that is capable of autonomous

action in this environment in order to meet its design

objetives”.

The need to develop complex applications

compound by multiple subsystems that interact with

each other does leverage the need to distribute the

responsabilities among different agents, moving us

to Multiagent Systems (in ahead MAS). Is generally

accepted that coordination is a key and

distinguishing characteristic in a MAS (Mas, 2005).

TOWARDS AN AGENT FRAMEWORK FOR A PASSENGER TRANSPORTATION VIRTUAL ENTERPRISE

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4 TOWARDS A FRAMEWORK

USING AGENT TECHNOLOGY

The Figure 1 shows a extract of the Agents

Identification Diagram, which takes as starting point

the description of UML use-cases, offering a general

view of all the functionality provided by the system

and in addition, it incorporates a grouping of use-

cases for each agent identified within the system in

order to visualize the responsability level that each

of the agents has regarding the system. It is possible

to indicate that the generation of diagrams is given

on the basis of the use of a graphical tool available

for PASSI, denominated PASSI Toolkit (PTK,

2007).

The VirtualEnterpriseAgent receives the transport

request and initiates a search of alternatives to

satisfy it, registering in the transaction system the

received transport request and the identifier of the

assigned vehicle. It handles information on all the

existing events. Considering the nature of the

triggered events, it can carry out changes and/or

apply countermeasures to the transport operators.

Furthermore, it can receive an affiliation request to

the virtual enterprise comming from a transport

operator and activates the mechanism to verify its

validity and feasibility. It can also drop from the

virtual transportation enterprise a specific operator.

The OperatorManagerAgent receives transport

requests from users and possible indications on

events caused by organizations external to the virtual

transport company. At any moment, it knows the

total number of vehicles available and the vehicles

that are in operation, and obtains the proposals to the

received requests of transport.

The ScheduleAgent verifies for a vehicle in

particular if it fulfills the conditions specified on a

requested trip (user conditions, conditions of the

virtual enterprise, or conditions caused by external

events), checking its itinerary obtained from the

information system of the transport operator.

Considering the feasibility verification, a proposal or

a declination takes place. For more details on the

underlying scheduling and optimization problem

please refer to (Cubillos et al. 2007)

A deployment/component hybrid diagram of the

general framework architecture is included (see

Figure 2). This initiative constitutes a first approach

in the conformation of a configurable and adaptable

architecture, based on object oriented and agent-

oriented technology together with considering the

virtual enterprise concept.

Inside each package a set of software components

are identified, those of which can correspond to

agents (as is the case of the package with the

<<Virtual Enterprise Terminal>> stereotype) or to

independent systems (as in the "Virtual Enterprise

Information System" package) or to a mixture of

both, agents with applications and managements

systems, as it happens in the case of the remaining

packages.

This architecture allows each transport operator

affiliated to the virtual transportation enterprise to

control at any moment the status of its operative

fleets, as well as to administer, if they wish, all the

information of their own information systems, in

such a way that independence between the different

operators of transport stays in the operative scope.

Each transport operator has his own mechanism

for allocation and control of the itineraries for the

different vehicles that conform his fleets, having the

virtual transportation enterprise the responsibility of

only receiving trip requests and the assignment of

these requests to the vehicle that constituted the

most attractive provider for the service user.

Anyway, the virtual transportation enterprise

maintains an own transaction system, in order to

requests, information and/or alerts from government

organizations or active destinations, among other

things.

Transport Operator

(from 01-Domain Descri

...)

Virtual Enterprise Information System

(from 01-Domain Description phase)

VirtualEnterpriseAgent

<<Agent>>

OperationManagerAgent

<<Agent>>

ScheduleAgent

<<Agent>>

Generate Proposals

(f rom ScheduleAgent)

Vehicle Itinerary

Management

(f rom ScheduleAgent)

<<communicate>>

Proposals Management

(f rom OperationManagerAgent)

Operative Fleet Visualising

(f rom OperationManagerAgent)

<<communicate>>

Virtual Enterprise Affiliation

Management

(f rom VirtualEnterpriseAgent)

Virtual Enterprise

Management

(f rom VirtualEnterpriseAgent)

Figure 1: Agent Identification Diagram for the Job-shop

scheduling system.

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5 CONCLUSIONS

The first version of a framework architecture for a

virtual enterprise devoted to passengers

transportation has been reached. The domain context

and their involved actors have been defined, which

can correspond to information systems or people.

The architecture includes a set of identified

agents which conform a society of agents and that

interact with both, the final user of the transport

system, and information systems and applications

external to it.

The future work will led to the refinement of the

software framework, verifying the points of

variability and the mechanisms of reusability.

ACKNOWLEDGEMENTS

Partially funded by Project No. 209.746/2007 of the

Pontifical Catholic University of Valparaíso

(www.pucv.cl).

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Cubillos, C., Crawford, B., Rodríguez, N. 2007.

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Figure 2: Deployment/Component hybrid diagram of the virtual enterprise framework.

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