Physics-Informed Exploratory Factor Analysis of Flow-Rate Impedance in Box Ship Hour Productivity

¹ Port Management and Maritime Logistics, Faculty of Engineering, Universitas Negeri Jakarta, Jl. Rawamangun Muka Raya, Rawamangun, Kota Jakarta Timur, Daerah Khusus Ibu Kota Jakarta 13320.
² School of Transportation & Logistics, Malaysia University of Science and Technology (MUST), Block B, Encorp Strand Garden Office, No. 12, Jalan PJU 5/1, Kota Damansara, Petaling Jaya, Selangor, Malaysia, 47810

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 2 July 2026

Abstract

Box Ship Hour (BSH) can be interpreted as a discrete flow rate variable because it measures the number of container boxes handled per vessel working hour. This research reformulates BSH productivity as an applied-physics problem in which container movement operates as a coupled flow system constrained by resource readiness, environmental disturbance, yard-space impedance, and digital-control responsiveness. This study does not directly measure physical flow variables,but interprets operational factors as flow-impedance modes and links them with secondary evidence of BSH decline. Questionnaire data were collected from 40 operational respondents at an international container terminal, supported by secondary operational reports. Thirty indicators covering loading-unloading equipment, container yard area, human resources, operational information technology, and weather conditions were analysed using Exploratory Factor Analysis. The instrument showed excellent reliability with Cronbach’s Alpha = 0.940, KMO = 0.780, and significant Bartlett’s Test results. Three dominant flow-impedance modes were identified: Resource Integration, Weather Disruption, and Container Yard Area, accounting for 69.745% of the total variance. Secondary operational data confirmed that crane adjustment, bad weather, truck/cargo waiting, system failure, and personnel waiting reduced BSH continuity. The novelty lies in translating BSH from a conventional logistics productivity indicator into a physics-informed flow-rate construct for diagnosing container-flow discontinuity.