# Blockchain and Self Sovereign Identity to Support Quality in the Food Supply Chain
## 2 Review
### Certifications in Food Supply Chain  
Let us start with the definition of supply chain and food product. As defined by [PERSON] and [PERSON] [6]  
...a supply chain is a sequence of processes and flows that take place within and between different stages and combine to fill a customer need for a product...The processes in a supply chain are divided into a series of cycles, each performed at the interface between two successive stages of a supply chain. Given the five stages of a supply chain (Customer, Retailer, Distributor, Manufacturer, Supplier), all supply chain processes can be broken down into the following four process cycles: Customer order cycle, Replenishment cycle, Manufacturing cycle, Procurement cycle. Each cycle occurs at the interface between two successive stages of the supply chain. Not every supply chain will have all four cycles clearly separated. For example, a grocery supply chain in which a retailer stocks finished-goods inventories and places replenishment orders with a distributor is likely to have all four cycles separated...  
A cycle view of the supply chain clearly defines the processes involved and the owners of each process. This view is useful when considering operational decisions because it specifies the roles and responsibilities of each member of the supply chain and the desired outcome for each process. As regards the definition of food, at a European level, a food product is first of all a food and as such it must respond to the basic principles of this type of good which are expressed by Regulation (EC) 178/2002, which involves the entire food chain including the primary phase (Ref. [[https://ec.europa.eu/info/food-farming-fisheries_en](https://ec.europa.eu/info/food-farming-fisheries_en)]([https://ec.europa.eu/info/food-farming-fisheries_en](https://ec.europa.eu/info/food-farming-fisheries_en)) (accessed on 15 November 2021)) upstream and the final market downstream. According to article 2 of the aforementioned regulation, food is defined as \"any substance or product processed, partially transformed or not processed, intended to be ingested, or which is reasonably expected to be ingested, by humans\". To be marketed, food products must comply with a canon of legality, which includes safety for the health of consumers and technical compliance with current regulations in terms of identity, process, and communication, which must meet the requirements of truthfulness and loyalty. Having respected the mandatory configuration of the food products defined by this regulation, it is possible to add voluntary requirements. These additional requirements must not conflict with the mandatory standards and must be substantial and objective to pursue the quality of the product. So, pursuing the product quality to increase it is therefore intended as an addition of requirements to those defined by the mandatory regulation. The pursuit of quality requires a precise and specific management that goes from planning to implementation, by the definition of methods, rules/procedures that have to be adapted to the real needs and business reality. A method that aims at the continuous improvement of processes and is at the same time a continuous guarantee of quality, is the Deming cycle. It is based on four moments--Plan, Do, Check, Act, (PDCA cycle)--and aims to promote a culture of quality to obtain continuous improvements of processes and the optimal use of resources [7]. Within a quality system we find the standards that define the requirements to be met, and the certifications that certify that the requirements are actually met. Certificationsare issued by third parties completely independent of the company that, after precise and accurate certifications processes, certify that a product, service, process, or company complies with the specified requirements. The certifications are divided into mandatory and voluntary [3; 8].