As the memory density and capacity grows, it is more likely that the number of defects increases. For this reason, in order to improve memory yield, repair analysis is widely used. Built-in redundancy analysis (BIRA) is regarded as one of the solutions to improve memory yield. However, the previous BIRA approaches require large hardware overhead to achieve the optimal repair rate. This is the main obstacle to use BIRA practically. Therefore, a new BIRA is proposed to reduce the hardware overhead significantly using spare allocation probability according to the number of faults on a sparse faulty line. The experimental results show that the hardware overhead of the proposed approach can be considerably reduced with slight loss of repair rate. Therefore, it can be used as a practical solution for BIRA.