International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 09 Issue: 08 | Aug 2022 www.irjet.net p-ISSN: 2395-0072 © 2022, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 1238 The Cuckoo Search Algorithm: A review. Shaunak Shiralkar 1 , Atharv Bahulekar 2 , Samidha Jawade 3 1 School of Mechanical Engineering, Dr Vishwanath Karad MIT World Peace University, Pune - 411038, Maharashtra, India 2,3 School of Mechanical Engineering, Dr Vishwanath Karad MIT World Peace University, Pune - 411038, Maharashtra, India --------------------------------------------------------------------***------------------------------------------------------------------- Abstract Today’s world is efficiency driven. All organizations irrespective of the type of industry they belong to, strive to achieve maximum efficiencies in their processes, this is where optimization comes into picture. It is mainly concerned with finding the optimum values for several decision variables to form a solution to an optimization problem . This paper aims to review the concept of Cuckoo Search Algorithm (CSA), which is a meta heuristic naturally inspired optimization algorithm. Further, the major improvements in the traditional CSA have also been reviewed. Finally the recent applications of the cuckoo search in optimization problems have also been presented in the form of a bibliographic review. This paper aims to be a one-stop article for researchers or readers who want to gain an overview of the concept of CSA and understand the concept thoroughly. Keywords: Meta-heuristic, Literature Review, Optimization, Cuckoo Search Algorithm. 1. Introduction Optimization is nothing but employing a maximising or minimising type decision making algorithm, adapted to methods of approximation[1]. The principle of decision making involves choosing between various alternatives. The result of this is to choose the best solution/decision from all the choices. These optimization algorithms are based on nature-derived concepts that deal with choosing the best alternative in the sense of the given objective function. An Optimization algorithms are mainly classified as: evolutionary algorithms (EAs), swarm-based algorithms, and trajectory- based algorithms. These algorithms emulate the principle called, The survival of the fittest. This starts with an initial group of individuals, called population[2]. At every generation, preferred characteristics of the current population are combined, and a new population, which is selected on the nasis of the principle of natural selection[1]. On the other hand, swarm-based algorithms mimic the behaviour of a group of animals when searching for food. Solutions are constructed normally, based on previous data collected by previous generations. At each iteration, that solution will be moved to its neighbouring solution, which resides in the same search space region, using a specific neighbourhood structure. In this paper, we will be focusing on the Cuckoo search algorithm[3]. There are thousands of bird species today, but the most commonly observed trait in birds is the way of reproduction. Birds reproduce by laying eggs. Since these eggs are rich in protein, and are the ultimate source of nourishment for predators, hence it is of utmost importance for the parent bird to protect its egg. The cunning behaviour shown by some bird species to secure or increase the survival rate of their next generation, is known as brood parasitism. Cuckoos show this type of behaviour. They never make their own nests but lay their eggs in other bird’s nests and thus if the eggs hatch, the host bird takes care of the cuckoo chicks. Cuckoo mothers show characteristics of stealth and speed. The mother cuckoo lays her egg in the host bird’s nest and removes one host egg and flies off within a few seconds. This entire process is extremely fast, which allows cuckoos to parasitise hundreds of bird species. Cuckoos specialise in a particular type of bird species. They accurately mimic their egg size, shape and colour, making it difficult for the host bird to identify the cuckoo egg. Exactly how the cuckoos manage to mimic the host bird is not known and rather is one of nature’s many unsolved mysteries. The host birds slowly learn to identify the cuckoo eggs and thus destroy them, hence the cuckoos have to continuously improve their strategy to lay their eggs in the host birds nests. Obligate brood species look for good environments where their chicks get well nourished. After these chicks grow into adults, they again carry on with the same life cycle. Hence this brood parasitism is passed on to the next generations.