Employing ontology and BIM to facilitate the information for subcontractor's payment requests and ledger generation

General contractors usually need to handle subcontractor's payment requests periodically according to the progress of the construction project. The documents required for payment requests are related to various types of information generated from construction work items. Consequently, construction company needs to spend a lot of efforts to verify and approve the submitted documents in order to record accounts on the ledger. Building Information Modeling (BIM) has been used to derive the information for various operations within the construction project. One of the important functions provided by BIM is quantity takeoff. With this capability, BIM can serve as an information platform to provide the information regarding various aggregated amounts of work required to be performed by subcontractors. However, detail information required to process payment requests is still hard to be obtained from the BIM model if no proper development specifications have been established. This study employs ontology and BIM to facilitate the information required to process payment requests and ledger. First, various work items performed by subcontractors are analyzed to identify the information required to process payment requests. Then the relationships between work items and BIM elements are determined through the ontology developed according to the required information identified. Next, a variety of Dynamo modules are applied to develop the BIM model that can provide various types of measurements required by work items. Finally, a database that can help construction managers to facilitate information for payment requests and ledger is developed for future uses.