6.3.3. Limited Scalability

Scalability can somehow contradict with the degree of decentralization defined in the current setting of blockchain implementations. The decentralized solutions generally take more computation time for the same set of operations performed with centralized solutions, such as NAS, and so it is expected that decentralized systems are generally less scalable than its centralized counterparts owing to the fact that consensus is needed for every state changed on the data of processed product records.

The multi-layered validation and creation mechanism of product records processed in the decentralized solutions could in all likelihood imply decreased scalability as they could now involve more steps to store or even update representations of any product record, given these state transitions on product records involved are required to be processed in the decentralized system components as well. In case the number and size of product records grow with more products circulating in the supply chain, longer computation time is definitely needed for these product record operations with more computation resources committed on data processing of product records stored in the off-chain backend database structure. Data stored and processed on decentralized system components, such as the blockchain network, should be kept minimum, given the computation resources needed for these decentralized processes could be exponential compared with its centralized counterparts. The requests sent to the existing microservices and blockchain interface could be handled sequentially for which a new request could be processed only if the previous one is completed. The single-threaded handling of these microservices, involved in any end-to-end product record operations, could possibly hinder the scalability of the decentralized solutions as a whole.

Given the extra decentralized processes required in the decentralized solutions from the point of invoking endpoints made available in blockchain interface all the way to the blockchain network. The size of the blockchain will grow over time with more transactions validated and packed in blocks mined, not to mention a new block could be created in an interval of block time defined when initiating the blockchain network. It could take fairly long period of time for any new blockchain node to synchronize with other blockchain nodes to ge<sup>t</sup> to the latest global states of the network. The long synchronization time would hinder the user experience for participants using the decentralized solutions when the size of blockchain is too bulk. Though there are potential scalability concerns on any proposed decentralized solutions, it is still worth decentralizing the supply chain anticounterfeiting and traceability, if comparing with the benefits brought by decentralization, such as the strengthened data integrity and improved system security with distributed instances enabling individual nodes along the supply chain collaborating to combat product counterfeits.
