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CHECKLIST EVALUATION OF INDIAN TRACTORS FOR HUMAN COMFORT WITH THE ASSESSMENT OF ITS REPEATABILITY

Viveksheel Rajput, Parveen Kalra, Jaswinder Singh

The productivity of operators and their performance are mainly depends upon the workspace in which he intends to work. This can be achieved only when they are comfortable in their workplaces designed for their best performance. Poorly designed tractors force operator to attain awkward posture which leads to musculoskeletal (MSDs) discomfort thereby reducing their efficiency and productivity. In order to eliminate discomfort study was conducted to evaluate tractor comfort from operator’s perspective and identifying poorly designed areas. Human comfort in tractors can be evaluated by direct involvement of the operators. In this study twenty operators were used to complete a questionnaire followed by an interview to get the detailed feedback of the tractor design. Objective of the thesis is (a) to evaluate tractor design for comfort (b) to identify poorly designed areas that need improvement (c) comparison of four tractor models (swaraj 855, ford 3630, Mahindra 555 and johndeere 5310) (d) to assess the repeatability of tractor design checklist. This study assessed the repeatability of a checklist designed to evaluate tractor design aspects that affect human discomfort. A series of task operations was performed by the operators on all the tractors sharing similar features. Operator’s opinion on the ease of entering, ease of exiting, PTO operations, operating pedals, operating tractors and overall comfort were collected on likert scale which is further used for evaluation analysis. Results showed that there are areas which need improvements in different design aspects in all tractors based on operator’s recommendations. Johndeere was rated as more comfortable among all the tractors. Repeatability assessment result shows that agreement in terms of kappa coefficients ranged from 0.61 to 1.0 (substantial-to-perfect reproducibility) across each tractor, and an overall kappa coefficient of 0.787 (substantial reproducibility) when considering all tractor together. The strength of kappa suggested that checklist is capable of identify areas that need improvement irrespective of the tractor model and observer used for evaluation.