Agricultural tractor cabin evaluationfrom users' perspective

Several ergonomic studies have shown that operators are more productive when their work environment is designed for the best human performance. Ergonomic requirements are issued in various standards and EU directives and need to be met by tractor manufactures. Among those, ISO 9241 defines usability as the effectiveness, efficiency and satisfaction with which users achieve specified goals in a particular context. The aspect of satisfaction in use is the most difficult to investigate as it is based on the evaluation of comfort and acceptability of the system by its users. Indeed, comfort is a subjective construct, requiring operators' direct involvement. The objective of this study was to evaluate tractors cabin comfort focusing on operators' perspective. Twenty tractor operators completed a questionnaire and a semi-structured interview after performing a series of tasks on an agricultural medium power tractor. Operators' opinions on ease of accessing the seat and the cabin, ease of exiting the cabin, concentration required in tasks execution, ease of locating and operating the controls, noise and visibility were collected. Results showed the need of improvements in different design aspects. Indeed, elements of bad ergonomic design were identified (e.g. some controls of the control panel did not match operators' task mental model).