Evaluation of the Project Cost Budget Plan for the XYZ Data Centre Construction Project Using My SMM and Regulation of the Director General of Construction Development No. 182 of 2025 Based on a WBS Integrated with Bim and Risk Analysis to Improve Cost Accuracy

Abstract

This study evaluates the accuracy of project cost budget planning for the XYZ Data Center construction using an integrated model combining WBS, BIM, the Malaysian Standard Method of Measurement (MY SMM), SE Director General of Construction Development No. 182 of 2025, and risk analysis. The research addresses the recurring issue of cost deviations in Indonesian construction projects, evidenced by significant discrepancies between estimated and actual costs in previous audits. The study employed a mixed-methods approach, incorporating qualitative analysis of project documentation, BIM-based quantity take-offs, surveys of 85 construction practitioners, and quantitative SEM-PLS analysis alongside Monte Carlo simulations for risk-based contingency costs. Findings reveal that WBS-based BIM significantly enhances the consistency and precision of quantity take-offs, reducing volume deviations to 0–5% compared to conventional manual methods. SEM-PLS results confirm that the cost estimation process positively and significantly impacts cost accuracy (? = 0.704, p = 0.006), with BIM as the most influential factor, while MY SMM and SE Director General standards have limited direct effect. Integration of risk contingencies further refines project cost predictions, increasing estimates by 8.10–16.10%. The study concludes that the proposed integrated model effectively improves cost estimation accuracy in complex data centre projects, providing a framework for standardized, risk-aware budgeting in Indonesian construction.