GAIA in Agent Oriented Software Development

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GAIA in Agent Oriented Software Development

• CS-564
• Tumpa Banerjee
• Class Presentation
• Wednesday December 7, 2005

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Topics

• Agent Oriented Software Development
• Multi Agent Software System
• GAIA Methodology
• Initial Limitations
• Overview of Gaia v.2
• Roadway
• References

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Agent Oriented Software Development

• an agent is an encapsulated computer system that
  is situated in some environment, and that is
  capable of flexible, autonomous action in that
  environment in order to meet its design
  objectives
• by Wooldrige
• Are Problem solving entities with well defined
  boundaries and interfaces
• Receive inputs to the state of that environment
  through their sensors and they act on the
  environment through their effectors
• Designed to fulfill particular job
• Autonomous i.e. have control over their internal
  state and behavior
• Capable of exhibiting flexible behavior

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Multi Agent Software System (MAS)

• Multi-agent system (MAS) is a system composed of
  several agents, capable of mutual interaction.
  The interaction can be in the form of message
  passing or producing changes in their common
  environment

Canonical view of a multi-agent system
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GAIA Methodology

• Gaia - a methodology for agent oriented analysis
  and design was introduced by 2000 by Michael
  Wooldridge, Nicholas R. Jennings and David Kinny
• Invented to start from requirement statements to
  detailed design that can be implemented directly.
• General
• wide range of multi-agent systems
• comprehensive
• macro-level (societal)
• micro-level (agent)

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GAIA methodology
Relationship between GAIAs Model
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GAIA methodology
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GAIA methodology
Analysis concept
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GAIA methodology (Analysis Concept)

• Analysis stage roles in the system identified
  and interaction modeled.
• Roles Abstract constructs used to
  conceptualize and understand the system, with no
  concrete counterpart in the implemented system
• All roles are atomic which cannot be defined in
  terms of other roles.

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GAIA methodology (Analysis Concept)

• It gives semi formal description of the
  behavior of the agent.
• There are 4 attributes of Role
• Permission gives the environmental resources
  available, generally specifying information as of
  read, write or create
• Responsibility it give the actual
  functionality
• Safety
• liveness
• Activity associated computations which can be
  performed by a agent without interacting with
  other agents
• Protocol Its is the way in which it is should
  interact with other roles.

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GAIA methodology (Analysis Concept)
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GAIA methodology (Analysis Concept)

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GAIA methodology (Analysis Concept)
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GAIA methodology (Design Concept)

• Agent Model documents various agent types that
  will be used in the system development, and the
  agent instances that are responsible for
  recognizing the agent types during the run time
• A
  sample agent design

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GAIA methodology (Design Concept)

• Service Model identifies the services
  associated with each agent role, and specify the
  main properties of the services.
• Service has 4 attributes
• Inputs
• Outputs
• Pre-conditions
• Post-conditions
• Acquaintance model defines the communication
  links that exists between agent types.

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GAIA methodology (Design Concept)

• Overall Design process
• Create an agent Model
• Aggregate roles into agent types , and refine to
  form an agent type hierarchy
• document the instances of each agent type using
  instance annotations.
• Develop a services model, by examining
  activities, protocols, and safety and liveness
  properties of roles.
• Develop an acquaintance model from the
  interaction model and agent model.

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Limitations

• designed to handle small-scale, closed
  agent-based systems
• Inappropriate in handling complex open systems
• Is not able to explicitly model and represent
  important social aspects of multi-agent systems.
  Specially it has problem with the system with
  merely nonrecursive roles. Also assumes all
  agents to be cooperative
• Employs Gaia specific notations for representing
  roles, which are poor in expressing complex
  problems.

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Overview of Gaia v.2
Requirements
Collection of requirements
Gaia Scope
Analysis
Subdivide System into sun Organizations
Environmental Model
Preliminary Role Model
Preliminary interaction Role Model
Organizational Rules
Design
Organizational Structure
Interaction Model
Organizational Patterns
Role Model
Agent Model
Service Model
Implementation
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Overview of Gaia v.2

• Analysis phase
• Goals of the organizations and their expected
  behavior
• Identify decomposition between global and sub
  organization
• Environment Model where the multiagent systems
  will be submitted
• Preliminary Roles Model unlike Gaia , the
  analysis has to avoid the imposition of specific
  organizational structure implicitly defined via
  the role model.
• Preliminary interaction Model abstact away from
  the organizational stucture
• Organizational Rules which governs the
  organization s global behavior.

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Overview of Gaia v.2

• Design Phase
• Definition of overall architecture of the system
• Huge number of different organizational
  structures a which opens up the opportunity to
  exploit existing catalogs of the organization
• Preliminary roles are revised and completed
• Define agent model specifying types
• Define service model (as in the original version)

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Roadmap

• Started in 2002 ,Juan et al is an extension of
  Gaia with dynamic hierarchy.
• Models are added to explicitly describe the agent
  environment and knowledge
• Follows the basic underlying principle as Gaia
• Follow the organizational view on multiagent
  systems and basic definitions

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Roadmap
System viewed as a computational organization
made up of the role hierarchy and the agent
hierarchy
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Roadmap
Message passing between agents via their roles
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Roadmap
Re-routing interaction with protocols
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Roadmap
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Roadmap
The ROADMAP meta-model
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Roadmap
Models in the Roadmap Methodology
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References

• The Gaia Methodology for Agent-Oriented Analysis
  and Design,
• MICHAEL WOOLDRIDGE, NICHOLAS R. JENNINGS, DAVID
  KINNY
• THE GAIA METHODOLOGY BASIC CONCEPTS AND
  EXTENSIONS
• Luca Cernuzzi1, Thomas Juan2, Leon Sterling2, and
  Franco Zambonell
• A survey of Agent Oriented Software Engineering
• Amund Tveit
• Agent Oriented Software Engineering
• N.R. Jennings ,Michael Wooldridge
• Figures are mostly taken from the above mentioned
  articles