This thesis mainly focuses on application of line balancing to minimize idle time of work station in production line. The methodology adopted includes calculation of cycle time of process, identifying bottleneck, calculating total work load on station, calculating the line efficiency, comparison of the existing and improved efficiency with numerical and graphically and distribution of work load on each workstation by line balancing, in order to improve the efficiency of line. Once the existing process is documented, all the assembly tasks involved must be timed using time study techniques. Assembly line balancing along with the associated operations analysis assists in constructing or re-configuring an assembly system, which is the key step in improving the overall performance of an assembly line. Following this approach, single line manual assembly is constructed for a case study. The research is consider on line balancing of a manufacturing industry; vehicle assembling at Bishuoftu Automotive Industry using the three methods namely, Ranked Positional Weight (RPW), Kilbridge and Wester's Column method (KWC) and Largest Candidate Rule (LCR). The research used a quantitative methodology to improve the productivity of vehicle assembly process using like graph with the help of Matlab- Software. The analyses indicated that the efficiency is improved from the existing 52.9% to 94.2% by using Ranked Positional Weight method as well as Largest Candidate Rule whereas by Kilbridge and Wester's method from 52.9 % to 80.4 %. On the other hand the cycle time is reduced from 63min to 50min, and manpower 80 to 47 respectively with reduction of number of work station from 16 to 12. These results show that the company save 13 min extra time and reduce extra space. The company is beneficial from reduced extra labor force, reduced number of work station, as well as reduced cycle time, this leads increase overall efficiency of the company These results show that the company increase the productivity by 44.5% this means will assemble extra 4 vehicles/shift. These results lead the factory meat their set production standard.