The objective of this study was to determine the dominance impacts of environmental factors such as illuminance (lx), operative temperature (°C), relative humidity (%), air flow velocity (m.s -1 ) on the operators' productivity at mechanical engineering industry. The subject were workers of the workstation space at the assembly section of the factory. Two sets of representative data level and production rate were collected by objective and subjective methods. All monitored factors were measured using calibrated multifunction apparatus which is capable to measure those mentioned environmental factors simultaneously. The obtained data from questionary survey realized in the same factory were statistical calculates with goal to identify the most significant factors from point of productivity view. Then was being utilized to find the sequence of dominance factors that contributed to the productivity of operator at the specified production workstation.