Beam local search - more states are retained (a population of states)

• evolutionary algorithms
• particle swarm optimisation
• ant colony optimisation

Swarm intelligence (collective intelligence)

A group of individuals that interact in order to achieve some objectives by collective adaptation to a global or local environment

Advantages:

• control is distributed among more individuals
• individuals local communicate
• system behaviour transcends the individual behaviour
• system is robust and can adapt to environment changes

Swarm

• more individuals, apparently non-organized, that are moving in order to form a group, but each individual seems to move in a particular direction
• inside the group can appear some social processes
• the collection is able to do complex tasks
  • without a guide or an external control
  • without a central coordination
• the collection can have performances better than the independent individuals

Collective adaptation → self-organisation

• set of dynamic mechanism that generates a global behaviour as a result of interaction among individual components
• rules that specify this interaction are executed based on local information only, without global references
• global behaviour is an emergent property of the system