Air carrier maintenance technician reported that while an aircraft tire was being changed at the gate; the supervisor allowed passenger boarding to commence; creating an unsafe situation.

Narrative

2 AMTs were assigned a work order on Aircraft X at gate XX. The work order included a maintenance discrepancy for a #1 MLG tire that required replacement. Prior to jacking the LH main landing gear; the AMT had directed the gate agents to hold boarding due to safety concerns as it was windy and the AMM (Aircraft Maintenance Manual)/ Job card specifically stated not to allow movement like of aircraft when refueling while on jacks. After jacking the aircraft the supervisor overstepped our instructions to the gate agent and told them to proceed with boarding the aircraft even when he was advised by our crew chief not to board based on the AMM instructions. Since we were busy changing the tire we were completely unaware that the passengers were boarding. Its was only until a brake fan operational check was required that we noticed that 1/3 of the passengers had already boarded. The aircraft did move because of the baggage; fuel and passenger movement and windy conditions. No damage was noted after the job was completed but the aircraft was moving and was unsafe for employees to work and passengers to board in that area. This should have never happened and could have been avoided by simply following the maintenance procedures and specifications through maintenance manual understanding the conditions we were facing at the gate performing the job.This should have never happened and could have been avoided by simply following the maintenance procedures and specifications through maintenance manual understanding the conditions we were facing at the gate performing the job.