The frame is divided into four layers, as shown in figure 1. The bottom layer is the sensor layer of the Internet of Things, which uses GPS to locate products in the logistics process. Using RFID technology to record quality information, asset information and transaction information. Various sensors will be used to collect information about temperature, vibration and humidity. Considering that many enterprises and CNC machine tools have their own information systems, we can develop some interfaces to obtain information from these different information systems.
The second layer is the data layer, including blockchain and distributed ledger. Blockchain stores quality data, logistics data, asset data and transaction data. In addition, all enterprises will keep copies of supply chain data, including suppliers, manufacturers, logistics operators, retailers and financial institutions. Smart contracts can use these data to perform quality control and improve the efficiency of the supply chain.
The third layer is the contract layer. Simple data sharing is not enough. The data collection of the above layers not only contributes to data sharing, but also aims to help quality control and improve efficiency. Privacy issues need to be considered when enjoying data. Because competing enterprises operate in the same supply chain, some information may need to be kept confidential, so digital identity can be used to control access to data. Smart contracts can use the data in the supply chain to perform real-time quality monitoring and automatic logistics planning. In addition, commercial contracts can also be automatically executed according to transaction data and smart contracts.
The top layer is the business layer. Including all kinds of business activities within the enterprise, every enterprise in the supply chain can control and manage the product quality with the support of blockchain and smart contract, so as to improve the efficiency and profit of the enterprise.
Case study:
In this section, we take the notebook computer supply chain as a case study. Suppliers in the supply chain provide parts for manufacturers and can monitor the production process and product quality in real time according to the data collected by IOT sensors and machine tools. In this way, suppliers and manufacturers can find and control errors in time. As shown in Figure 2, the quality data in the production process and inspection process will be uploaded and stored in the blockchain, and the quality data, process quality and product quality will be evaluated in real time through smart contracts, and the results will be fed back to suppliers, manufacturers and retailers.
Figure 2: Real-time quality monitoring
Competing vendors in Guan Xu may provide the same type of components, such as CPU or screen. Under the control of smart contracts, each supplier has its own digital identity and has specific access rights to the data on the blockchain. For example, Intel and AMD cannot access each other's data. As shown in Figure 3, enterprises in the supply chain can upload data without restriction, and control data access rights through smart contracts with digital identities, thus ensuring data privacy.
Figure 3: Digital Identity
There are also contracts between manufacturers and suppliers. For example, if the smart contract detects that some products cannot meet the manufacturer's requirements, these products will be automatically returned. As shown in Figure 4, smart contracts should be deployed on both sides, and the contracts will be automatically executed. When unexpected errors occur, the execution results will be sent to stakeholders.
Figure 4: Smart contracts
All suppliers of blockchain can get customer feedback on products in order to adjust production.
In the process of logistics, sensors detect environmental data, including temperature and humidity, and GPS tracks the position of products. Based on these data, logistics providers can use smart contracts to automatically plan their routes and transportation modes. As shown in Figure 5, suppliers and manufacturers upload transportation data, and smart contracts make logistics plans according to the quantity and location of products.
Figure 5: Logistics Plan
Retailers use smart contracts to monitor the production process and product quality. When an internal fault occurs, the product is cancelled; When external faults occur, retailers and manufacturers bear the losses according to their quality contracts. Manufacturers can also get the final customer demand analysis and feedback in order to adjust the production strategy. All these processes are automated through smart contracts.
Supply chain finance is another important part of the system. When the enterprise is short of funds, financial institutions can provide product mortgage loans for enterprises in the supply chain by using asset data, logistics data and transaction data. According to the loan contract, these mortgage products are protected by smart contracts. As shown in Figure 6, financial institutions can access the loan data enjoyed by suppliers, manufacturers, logistics providers and retailers to evaluate the ability of enterprises to repay loans.
Figure 6: Supply chain financial system
Therefore, blockchain and smart contracts have established a more reliable quality monitoring system, a more flexible end-customer demand feedback system and a safer and more convenient supply chain financial system.
The main data, we analyze the reasons of factory quality management data.