3) OWAS analysis was done at the recommended time interval of 30 s, in the second, third, and fourth hour in the morning and the afternoon. The first and last hours of the journey were ruled out assuming workers were not in their full capacity in the beginning (because they are warming up) and at the end(because they are tired) of the journey. Therefore 360 images were evaluated for each of the 4 tasks: frame assembly, straps placement, foam gluing and upholstery.Workers were picked at random in the diagnosis stage (pre-evaluation) because the analysis considered the worker on videotape at the selected time. However, the same eleven workers were on tape and
evaluated in the validation stage (post evaluation).