The most important thing of the improvement of cluster design is to make a big cluster. To content with this requirement needs some satisfaction of package requirement. First of all, A cluster size belongs to a package rim obstruction curve. The package rim obstruction curve contains several cluster warning symbols and figures. From now on, I will investigate this package rim obstruction and suggest new method of rim obstruction. I suggest the guide method of checking obstruction. So I will recommend a bigger cluster size.