Prediction of postural discomfort impact on manual assembly: A workshop case study

Abstract

The analysis of manual assembly features and performance indicators is well reported in the literature. Awkward working postures and energy expenditure are known to be the major elements affecting the ergonomic of the manual assembler. However, such investigations are not fully discussed in non-repetitive operations. We therefore conducted a comprehensive ergonomic analysis of the manual assembly process of a SAE Baja racing car at a Mechanical Skills Workshop. Through an experimental set-up to collect data, the observation of the manual assembly operation of a SAE Baja racing car was performed. Purposeful sampling determined the specific elements that were critical to the analysis. The postural disposition of an assembler performing 24 similar work elements was studied. According to REBA, the assembly operations required further investigation and change. Based on the essential assembly-ergonomic components of the study, the energy expenditure of the tasks was derived, and the coefficients of determination R2 gave an indication of the level of correlation between the parameters of the manual assembly operation. To complete the study, we give examples of corrective measures that could formalize the working postures of the assembler, thus reducing the risk of physical discomfort and, subsequently helping in sustaining manual assembly operations.