Short message service (SMS) that has been widely
used in various fields could potentially utilized for problemsolving
consulting services that are based on expert system, so it
takes a kind of application platform to implement this service.
This paper proposes an expansion of online expert system
services (web and wap based) by adding an application use SMS
interface. Knowledge base of the expert system, which employs a
decision tree approach, is expressed in the form of a database
that can be accessed by the application interfaces, including SMS
interface. According to the experiment results, the decision tree
has been able to play a role directing the consultation mechanism
from an initial question to reach a conclusion interactively. Thus,
a problem-solving case that can be expressed in the decision tree
allows the implementation of this system.