## 1 Introduction  
The term '_Industry 4.0_' initially originated from Germany, and it represents the fourth industrial revolution [1]. Industry 4.0 is still visionary but realistic [2] as technology is changing faster than ever. A summary of the industrial revolutions [3, 4, 5, 6] is given below in Figure 1.  
Pre-Industrial societies were small, rural, and largely dependent on local resources. For centuries, goods were manufactured manually or by using work animals. This trend continued until the start of the first industrial revolution, i.e., Industry 1.0 in the 18 th Century. Industry 1.0 introduced the mechanical production facilities with the help of water and steam power. The second industrial revolution, i.e., Industry 2.0 started in the 19 th century with the invention of electricity. Industry 2.0 replaced the steam power with electrical power and introduced the concept of automation and assembly lines. The third industrial revolution started in the 20 th century with the invention of computer technology. Industry 3.0 introduced the digitalization of technology and further helped to automate the factory using computer systems. The fourth industrial revolution, i.e., Industry 4.0, is happening now, and its concept is based on digitalization, automation, and interconnected smart industry [7], often termed Cyber Physical systems. Industry 4.0 is mainly about how advanced technologies are brought together and utilized to build a smart manufacturing environment. The digitalization concept of Industry 4.0 involves the digitalization of all the industrial processes that make up the value chain. This digitalization enables companies to combine learnings from machines, analytics, and predictive insights to make better decisions. Conventionally, manufacturing processes were simply monitored but Industry 4.0 focuses on fully connected manufacturing and logistics processes. This leads to smarter decisions, better ability to predict future needs, better-designed products, and more efficient use of resources. Connected technologies transform the way products are developed, and this enables rapid prototyping and testing by adding connectivity to previously unconnected products and leads to new products and services. The goal of Industry 4.0 is the \"smart factory\" with cyber-physical systems capable of autonomously exchanging information, triggering actions, and controlling each other independently. Technologies that form building blocks of the Industry 4.0 [8; 9; 10] are Big data and analytics, Industrial Internet of Things, Cybersecurity, Cloud computing, Additive Manufacturing, Simulation, Augmented Reality, and Cyber-Physical Systems. In addition, Manufacturing Execution Systems (MESs) and Autonomous Intelligent Vehicles (AIVs) are critical components of Industry 4.0 [8; 11] in order to achieve interconnection and automation objectives. This work focuses on the integration of these two components. An MES [12], is an information system that connects, monitors, and controls data flows on the factory floor in real-time. This system will act as an enabler to attain the end to end digitization and interconnectivity objectives of Industry 4.0. This is because the MES acts as a bridge between different plant floor systems and provides real-time information exchange for faster and better decision making. Figure 1: The four industrial revolutions. All resources involved in the production process can be interconnected using the MES to support a smarter manufacturing process. AIVs are used across countless industries, including manufacturing [13]. Companies that aim to have a smart factory to facilitate Industry 4.0 must integrate robotics into its operations. By connecting AIVs to a programmable logic controller, central server, or database, the actions of robots can be automated and coordinated. AIVs can complete tasks intelligently and in an organized manner with minimal human input.