Factors in Logistics and Supply Chain Management Affecting the Duration of Metro Tunnel Excavation Using a Tunnel Boring Machine (TBM): A Case Study of Unique Engineering and Construction Public Company Limited

Abstract

This study aimed to (1) examine logistics and supply chain management factors related to metro rail tunnel excavation using Tunnel Boring Machines (TBMs), (2) analyze the relationship between logistics and supply chain factors and tunnel excavation duration, and (3) propose improvement strategies for logistics and supply chain management to reduce project timelines. A mixed-methods approach was employed, collecting data from 120 project managers, field engineers, and logistics personnel at Unique Engineering and Construction Public Company Limited through questionnaires, in-depth interviews, and focus group discussions. Quantitative data were analyzed using descriptive and inferential statistics, while qualitative data underwent content analysis.

The findings revealed that (1) procurement planning, material warehouse management, transportation, and supply chain information communication were significant factors highly related to TBM tunnel excavation, (2) logistics and supply chain management factors demonstrated statistically significant negative correlations with tunnel excavation duration, indicating that efficient management reduces project delays, and (3) proposed improvements include integrated planning, information management, and inter-departmental coordination to enhance TBM operational continuity and reduce overall project duration. This research provides systematic insights into the role of logistics and supply chain management in TBM tunnel projects and offers practical applications for future rail system construction projects.