Ergonomics simulation models Redesign of a hand pallet truck by integrating ergonomics analysis and quality function deployment.

Isa Halim et al. AJE Vol.9 2009 109-121 118 Figure 5. A manikin simulates the pushing and pulling activities using existing HPT Figure 6 . A manikin demonstrates the pushing and pulling activities using redesigned HPT When pushing the redesigned HPT, the maximum acceptable initial force is 319.874 N, and the maximum acceptable sustained force is 167.064 N; when pulling, the maximum acceptable initial force is 273.212 N, and the maximum acceptable sustained force is 153.302 N Figure 6

8. Discussion

This section discusses the findings of study. Based on the questionnaire survey, workers identified “easy to maneuver”, “stability of load”, and “able to carry various sizes of object” as the most important requirements for an HPT. Priorities were developed in the HoQ to determine which technical specifications must be considered in HPT design. Based on the technical relative importance and percentage importance, a designer should focus on the following specifications to redesign the HPT: “width of fork”, “size of load supporter”, “overall width”, and “wheel size wide”. These technical specifications were incorporated in the new design of HPT to accommodate workers’ requirements such as “able to carry various sizes of object”, “easy to maneuver” and “stability of load”. The existing HPT has been redesigned by considering all workers’ requirements as identified using QFD method. Both existing HPT and redesigned HPT were analyzed to determine their maximum acceptable initial force and maximum acceptable sustained force during pushing and pulling activities. Through this analysis, the workers can determine the limit of forces that they should exert to avoid having a significant chance of being injured or developing occupational injuries. The results of analysis showed that the existing and redesigned HPT have different force limits for pushing and pulling activities Section 7. To avoid the risk of injury, workers should respect those limits when performing pushing and pulling activities using either existing design or redesigned HPT. The force limits were not changes significantly by the redesign Table 4, but this finding is essential to minimize the stresses on the workers when handling the HPT and reduce the risk of occupational injuries.