The digital transformation in the existing supply chain and manufacturing system is the need of the hour. Smart factories are one of the suitable examples for this digital transformation occurring in the Fourth Industrial Revolution Industry 4.0 and intelligent automation. To meet the customized and dynamic demand of the products, the digital manufacturing is playing an important role. In smart factories, the machines, communication mechanism, production system, etc. are interconnected via cyber-physical system (CPS), Internet of Things (IOT), artificial intelligence (AI), and machine learning (ML). CPS is the key technology to integrate virtual and physical worlds in which intelligent objects can communicate in smart factories. Cyber-physical system is basically a combination of electrical, electronics, and software that can communicate through a data infrastructure such as internet, and it can also exchange information/data with other systems. Cyber-physical systems work as the “thing” on the Internet of Things. Data collection, machine to machine interaction, and machine to operator interaction in a smart factory are feasible through cyber-physical systems only. Therefore, a factory is called smart factory after the implementation of cyber-physical system.