# Smart Manufacturing Application in Precision Manufacturing
## 2 Methodology
### Connectivity Stage  
Connectivity is the backbone of industry 4.0. It is related to the interconnectedness of the OT that resides within the factory floor (e.g., machines) and the IT that resides in the enterprise (e.g., computer-based systems). The concept of connectivity under industry 4.0 means more devices and systems that once were independent and/or isolated are being connected via digital means to generate enormous amounts of manufacturing data that can be easily accessed. However, formal connections need to be established across assets and systems to ensure the interoperability, security, speed, and agility of the network. These qualities allow interconnected systems to communicate with one another seamlessly and allow them to be reconfigured dynamically in response to changing needs [22]. In this stage, the scope was to connect the CNC machines. The starting point was to enhance the network infrastructure in the factory with stable, resilient, and secure capabilities for seamless connectivity. A dedicated factory network server was installed and segregated from the enterprise network using two Cisco Industrial Ethernet (IE) 4000 switches provided by Mazak's SMARTBOX(tm) (Mazak Corporation, Takeda, Japan) technology [33; 34], embedded with a high level of network security protocols to prevent any issues with unauthorized access from and to the machines on the network, safeguarding the manufacturing process. They were mounted to the sidewall of the factory and connected to the machines via network ethernet cables; direct connection to the machine's electrical cabinet was not needed. Figure 3: Base state of integrated manufacturing system architecture: (**a**) ISA-95 diagram; (**b**) manufacturing system connectivity and integration architecture. The connectivity to the CNC machines was established using an ecosystem of technology elements that collected, stored, and visualized the data of the machine's condition and the machining process. The technology stack provided by Mazak's iSMART Factory(tm) solution [33] represented a cost-effective yet secure by-design digital connectivity solution for the CNC machines. MTConnect communication protocols were used as the standard methods for communication and data representation, which have been widely used in industrial environments [35]. The technology layers of the iSMART Factory ecosystem solution consisted of an IIoT gateway communication layer and an application management layer. The IIoT gateway consisted of four sublayers: Thing, Sensor, Edge, and Communication. The Thing was the actual CNC machine with its actuators (e.g., 3-5 axes spindle). The Sensor was the sensor embedded within the CNC machine itself manufactured by the OEM, and the Edge was the PLC unit that operated and controlled the CNC machine. The Communication layers consisted of software adapters, ethernet network cables, and software agents. The software adapter (MTConnect-based) used an industrial standard communication protocol for data extraction that was installed on the CNC machine control computer operator that controlled the PLC. The Ethernet network was the communication method of transporting data through the network from the CNC machine through the industrial switch to the server. The software agent (MTConnect-based) was installed inside the industrial switch (Mazak Smart Box) that had computing capability, allowing the software agent to interpret the relevant manufacturing data from multiple machines connected to the industrial switch before they were passed to the client application management at the server. This industrial network switch also acted as north/south bound network cybersecurity divider layer with secure network connectivity features, allowing device verification and the one-direction flow of data from the factory floor network to the office network, safeguarding CNC machines connected and preventing vulnerable hacks that can leak information, damage equipment, or even cause personal injury. The application management layer consisted of a Smooth Monitor AX and a database.