Smarter smart contracts for automatic BIM metadata compliance checking in blockchain-enabled common data environment

Blockchain technology is gaining increasing attention in BIM -based collaboration to enhance BIM security (e.g., traceability, integrity, and immutability). Due to the block size limitation, most existing BIM-blockchain interactions focus on recording BIM metadata (or attributes) on the blockchain. However, verifying the correctness or compliance of the input metadata is often overlooked, resulting in the sharing of incorrect versions, disputes over data ownership, and corrupted documents. Two research gaps have been identified: (1) a lack of domain knowledge for metadata compliance checking in BIM collaborative design and (2) an absence of methods to perform compliance checking when interacting with blockchain. Therefore, this paper proposes a blockchainenabled common data environment (BECDE) framework that leverages a knowledge graph (KG) and smart contract technology. This framework makes three contributions to the body of knowledge: (1) It explores the mechanism of integrating KG with smart contracts and the CDE workflow to enable compliance checking in a distributed blockchain environment. Within this framework, two essential technical elements -compliance checking rules (CCRs) and "smarter " smart contracts (SSCs) -are identified. (2) It establishes the KG of the ISO 19650 standards to generate CCRs and develops Semantic Web Rule Language (SWRL) algorithms to convert the natural -language -based CCRs into blockchain-readable rules. (3) It develops SSC algorithms by incorporating CCRs to automate checking BIM metadata compliance before appending them to the blockchain. The BECDE framework is validated in three actual project BIM design scenarios, with results showing that (1) the SSCs outperform existing BIM smart contracts by improving the quality of input data within the blockchain and (2) the computing performances of the SSCs -with latency at the millisecond level and throughput around 250 transactions per second -meet the requirements of BIM -based collaboration. By integrating domain knowledge into a blockchain, the BECDE framework facilitates a trustworthy BIM environment where project members can rely on both data security and quality.