Particle swarm optimisation for discrete optimisation problems: a review

In many optimisation problems, all or some of decision variables are discrete. Solving such problems are more challenging than those problems with pure continuous variables. Among various optimisation techniques, particle swarm optimisation (PSO) has demonstrated more promising performance in tackling discrete optimisation problems. In PSO, basic variants are merely applicable to continuous problems. So, appropriate strategies should be adopted for enabling them to be applicable to discrete problems. This paper analyses all strategies adopted in PSO for tackling discrete problems and discusses thoroughly about pros and cons of each strategy.