Availability of large amount and variety of information and decision making problems in various complex systems ranging from transportation, supply chain, energy to logistics; have placed the need for the development & successful application of advanced intelligent approaches. It is argued that intelligent approaches such as analytics and optimisation techniques drive smarter decisions, faster actions and optimise outcomes in this era. However, there are no single best analytical or optimisation technique to deal with the challenges in various complex systems. It is due to the fact that a technique/approach may show a better performance for a given problem instance; but, it does not guarantee better solution when applied to decision making problems in other areas. Hence, the development of new solution techniques or modifications of existing techniques are very much needed to suit the decision making problem at hand. This special issue focuses on fast-growing and promising area of intelligent approaches applied to complex systems that have drawn great deal of attention from researchers over the years.