Variants of Ant Colony Optimization- A State of an Art

Ant Colony Optimization, a Swarm intelligence method which solves NP hard problems inspired from the behaviour of ant foraging (Searching for food) the heuristics they use and partial guidance by other ants in indirect format (Stigmergy). This paper developed to list out the variations of the ACO application, its variants with clear diagrammatic and graphical representation. Clear denotation of the techniques they have used to solve such problems, representation of problems, transformations, parameters used and advantage of the techniques and used variants. Through this article we identify some open suggestions with a certain interest of being solved in near future.