The RULA is a practical method in terms of saving time and resources; however the precision of this tool could be affected by lack of information such as duration of the task, available recovery time, or hand-arm vibration. Moreover, the tool may require several RULA assessments for one task. After the interview and observation of the worker, it is possible to determine the criticality of the job task: if only one arm should be evaluated or if the assessment is needed for both sides, that's why usually it is recommended choose the most extreme posture to evaluate.