Digital Human Modelling–Driven Ergonomic Risk Assessment, Workstation Redesign, and Usability Evaluation in a Manufacturing Assembly Line

Abstract

This study applies a digital human modelling–driven approach to ergonomic risk assessment, workstation redesign, and usability evaluation in a manufacturing assembly line. Work-related musculoskeletal disorders (WMSDs) remain a major occupational health concern in manufacturing environments, particularly in standing manual assembly workstations. Inadequate workstation design often leads to awkward postures, prolonged static loading, and repetitive movements, contributing to discomfort, fatigue, and reduced productivity. This study evaluates ergonomic risks associated with working postures at a manual insert workstation in an air-conditioner manufacturing company using Digital Human Modelling (DHM) integrated with Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA). A cross-sectional assessment involving ten female operators was conducted using observational analysis, anthropometric measurement, and the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ). Existing work postures were simulated in CATIA to quantify ergonomic risk levels. Based on identified risk factors, an ergonomically improved workstation was designed and re-evaluated using RULA. Results showed that the existing workstation posed medium to very high ergonomic risks (RULA scores up to 7; REBA scores up to 11), particularly affecting the neck, lower back, and lower limbs. The redesigned workstation reduced the RULA score to 3, indicating a substantial improvement in postural risk. The findings demonstrate the effectiveness of DHM-supported ergonomic interventions in reducing WMSDs risk and highlight the importance of user-centered workstation design in manufacturing settings.