To provide a method for deciding not a simple statistical probability but a block of an actual line from data by using a method for obtaining and processing data regarding individual call blocks and judging whether many of the blocks are generated by a single line or by more lines.

This computer system 100 receives data from a load balance process and stores these load balance data 106 in a memory 104. Next, the computer system 100 uses a program 108 stored in the memory 104, reads a result of the load balance data 106, analyzes and stores it. Then, in order to analyze the load balance data 106, a line identification service process method is used. This method can quickly find individual lines which induce call blocks, report them, find that groups of specific lines get together and induce the call block, and report it.