Now a days, the Work-related Musculoskeletal Disorders (WMSDs) are considered as principal ergonomic aspect in terms of occupational safety. The operators maintained various most strenuous postures while performing the repetitive assembly tasks. These most strenuous postures and repetitive movements of the assembly operator cause WMSDs which includes carpal tunnel syndrome, tendonitis, thoracic outlet syndrome, and neck syndrome etc. These disorders cause extreme fatigue in the body of working operators which inferiors their performance. The present study aims to reduce the risk level of WMSDs in the body of working operators. In this study, an observation method; Occupational Repetitive Actions (OCRA) index is used to estimate and minimize the risk level of WMSDs. The OCRA index provides a value for determining the percentage of the operators affected by the WMSDs among the entire working populace.