# Overcoming the Technological Barriers in the Blockchain Supply Chain for Small Carriers
## 2 Related Work
### Applications in the Supply Chain  
One of the most exciting challenges in the field of blockchain applications is the supply chain. There can already be separate technologies already in production, shipment tracking, quality control, or other parameters, and payment. In theory, blockchain technology can have various applications in the supply chain. Successful integration of blockchain technology in supply chain management necessitates cooperation among all involved parties and the establishment of suitable legal and regulatory structures [39]. [PERSON] et al. [40] presented the benefits of blockchain in the supply chain. The literature review from the management integration perspective is given [41]. Several authors presented theoretical models. [PERSON] [42] developed a blockchain-based Logistics Monitoring System (BLMS) prototype. The purpose of the BLMS was to provide a solution to track packages and provide an open and immutable history record for each transaction within the supply chain. [PERSON] et al. [43] proposed AgriBlockIoT, a decentralised blockchain-based traceability solution for agri-food supply chain management that can integrate IoT devices. The proposed system could give consumers a complete overview of their food, from farm to consumption. The system can be integrated into existing systems (ERP, CRM, etc.). An interesting concept has been proposed by [PERSON] et al. [44]. It is about blockchain-based supply chain management and smart contracts for e-agro business systems. The basis of the proposal is an open platform for suppliers and buyers where they can negotiate prices for goods. In addition, tracking and tracing of goods is possible by deploying IoT sensors and devices and the smart contracts used. There are already supply chain traceability systems based on blockchain [45; 46]. However, these do not account for the change (transformation) of goods in the production processes. This significantly complicates the traceability of the origin of the goods unless a the change in the structure of the original goods is assumed. Therefore, the authors [47] proposed a blockchain-based supply chain management system that enables tracking and tracing goods, including their transformation (change) in the production process using smart contracts. In smart contracts, manufacturers define the composition of products in the form of recipes. Some studies deal with real-world use cases of blockchain technology in the supply chain. [PERSON] et al. [48] proposed a platform based on Algorand blockchain [49] designed to track and trace the supply chain of Fontina DOP cheese. Supply chain operators record all transactions but send data in JSON format to the Algorand platform only at the packaging stage. This reduces energy consumption, resulting in minimal environmental impact and a cost reduction. The platform has been tested and validated in dairy farms in the Aosta Valley in Italy. The authors claim that the proposed architecture and design can be applied to any other dairy supply chain. Another study [50] describes another actual use case for blockchain. This pilot project aims to track and trace eggs from the farm to the consumer. Consumers can scan a QR code and gain access to information about the entire supply chain. The system is based on IoT technology. They are already proven business solutions linked to companies such as IBM [51] or AMAZON [52]. An essential part of the supply chain is the shipping process. Especially in the cold supply chain, monitoring the required temperature during transport is necessary. SkyCell has created air freight containers based on IoT and blockchain technology to transport goods at controlled temperatures. The solution is that an IoT device is placed in each container, which allows real-time data to be captured. This data is then stored in a blockchain and made visible to all participants in the supply chain. Supply chain actors can react to temperature changes in a short time and thus prevent the goods being transported from spoiling [53].