This paper presents data for estimating the production efficiency of automatic assembling lines, with calculations and considerations for numerical examples. The efficiency of assembling lines is influenced by the trouble rate, the recovery time and the buffer capacity of each assembling station. Calculations and considerations are performed for various of those factors by use of the method proposed previously. The main results reported in this paper are as follows : (1) The efficiency increases with buffer capacity in b12/Ri < 2.0 (b12 ; buffer capacity, Ri ; a multiple of the cycle time) and takes approximately a constant value in b12/Ri >2.0. (2) As the number of stations increases, the effect of the capacity increases. (3) The efficiency takes maximum value at the same trouble rate and recovery time in each stations.