## 2 Theoretical Background and Literature Review
### Blockchain and Smart Contracts
#### 2.2.4 Smart Contracts: Automating Trust in Blockchain  
Smart contracts represent a significant innovation in the blockchain space. Conceptualized by [PERSON] in 1994 [74], these are self-executing contracts where the terms of agreement are directly written into code and run on the blockchain. They are designed to automatically execute and enforce contracts, thereby enhancing the reliability of transactions and minimizing the risk of breaches. The practical applications of smart contracts are vast and varied. In the financial sector, they are revolutionizing processes like the trading of financial instruments and the management of insurance claims, introducing unprecedented levels of operational efficiency. In manufacturing, smart contracts are increasingly being used to manage production stages, enhancing both productivity and product quality. Beyond finance and manufacturing, the potential applications of smart contracts extend to areas such as smart cities, where they can manage real estate transactions, and healthcare, where they can secure patient data and manage treatment protocols. This wide applicability is indicative of the transformative potential of smart contracts, which are evolving rapidly on the backbone of blockchain technology [75; 76; 77; 78; 79; 80; 81; 82]. Smart contracts are significantly enhancing the integrity and efficiency of various processes by automating trust and transaction execution. As this technology matures, it is expected to drive innovative changes across numerous fields, including the 5G ceramic antenna manufacturing process. The integration of smart contracts in manufacturing processes, particularly in complex and technologically advanced fields like 5G antenna production, could lead to significant improvements in efficiency, transparency, and quality control, marking a new era in manufacturing practices. In our previous research [38], we embarked on a comprehensive exploration of the integration of blockchain technology within the 5G antenna manufacturing domain. This investigation was driven by the recognition of blockchain's potential to fundamentally transform manufacturing processes by enhancing data integrity, ensuring transparency, and facilitating secure and efficient transactions across the supply chain. Our study delineated a blockchain-based framework specifically tailored for the manufacturing of 5G ceramic antennas. This framework leverages the immutable and decentralized characteristics of blockchain to create a transparent and secure record-keeping system. Such a system is instrumental in mitigating common challenges in manufacturing, including supply chain opacity, data tampering, and the inefficient reconciliation of transactions. Through the deployment of smart contracts, our approach automates key processes within the manufacturing and supply chain operations,significantly reducing manual interventions, minimizing errors, and streamlining workflow. This automation extends to compliance verification, quality control measures, and logistical coordination, thereby enhancing operational efficiency and reducing lead times. Crucially, our research highlighted the blockchain's capacity to foster a collaborative ecosystem among stakeholders, including manufacturers, suppliers, regulators, and customers. By providing a shared and trusted ledger, blockchain technology facilitates a higher degree of collaboration and trust. This collaborative environment is essential for addressing the complex demands of 5G antenna manufacturing, characterized by stringent quality requirements and the need for agile response to market changes. Furthermore, our analysis shed light on the blockchain's role in improving traceability and accountability throughout the antenna manufacturing process. This improvement is particularly relevant in the context of ensuring compliance with evolving industry standards and environmental regulations.