In the past 40 years, many kinds of simulation methods of micro phase separation of block copolymer were proposed. Each technic has some features derived from the original theory, and has strong and weak points in each simulation. We have developed the simulation software OCTA and performed the application study of OCTA to analyze the micro phase separated structure. In this paper, these simulation technics for micro phase separation of block copolymer are explained as a showcase of those technics from the point of view of DSA analysis. The advantages and disadvantages of these methods in the application study of DSA are indicated. I hope that this paper becomes the compass to select the suitable simulation method to analyze each DSA problem.