Smart Factory and 5th Generation Mobile Communication Systems gained much scientific and business attention during the years before the COVID-19 pandemic, as part of the so-called 4th Industrial Revolution (Industry 4.0). Even though there are second thoughts about whether the pandemic crisis will slow up Industry's 4.0 implementation, there has been an acceleration in the use of intelligent and reliable communications solutions in all business aspects, leading to the need for deepening our understanding about digital transformation and digitalization strategies. The current chapter aims to describe the concept of Smart Factory as a key factor of the 4th Industrial Revolution and to deliver its most important factors for a successful implementation. Moreover, smart factory is interrelated with 5th generation of mobile communication systems (5G), which seems to offer the capabilities needed for the advanced industrial digitalization.