A SMS based ES has been developed in [12] and [13], although those works are only specified for specific cases. In [12], expert system applications using SMS for fish disease cases with a case-based reasoning approach. While in [13], SMS based expert system use fuzzy approach to case of crops field. Both of these applications require particular design for the implementation because it uses some parameters that need to be considered analytically. While at the other cases it may take more general representation such as with decision tree approach. So the chances of its use will be more flexible.