the present invention is a method of quality assurance and rectification of defects in the process of assembling a vehicle on a continuously moving assembly line . the method includes the steps of providing a continuously moving assembly line for assembly of vehicles and providing assembly stations along the length of the continuously moving assembly line attended by operators who perform discrete assigned tasks on incomplete vehicles positioned on the continuously moving assembly line as the incomplete vehicles pass by , leading to building of complete vehicles . the method also includes providing an assembly data input terminal at each assembly station , with each data input terminal having a plurality of manually actuatable switches corresponding to a discrete assigned tasks of an operator . the operators manipulate the switches to indicate successful or unsuccessful completion of discrete assigned tasks with respect to specific incomplete vehicles . the steps include communicating the input data from the assembly data input terminals to a central computer and providing a limit switch at each assembly station which is tripped by a vehicle carrier of the assembly line . the steps further include communicating a signal from the tripped limit switch to a sequencing computer and coordinating assembly station and vehicle data with a line tracking number for the previous vehicle of the assembly station .