Expert systems (expert systems) is a system that uses human knowledge, where knowledge is put
into a computer, and then used to solve problems that normally require human expertise or skill.
In this case, the expert system is used to determine the type of disease stage of typhoid fever, in
which there are several types of typhoid stage that can be experienced by anyone, because it is in
this case, systems of experts is used to help people who want to know the type of typhoid stage in
the suffering , which in this case there are four types of stages are discussed, namely incremasi
stage, acme stage, stage deternasi and recofalesent stage. In the application of expert systems is
aided by using Depmster-Shafer. Dempster-Shafer is a mathematical theory of evidence based on
belief functions and plausible reasoning (belief functions and plausible thinking), which is used to
combine separate pieces of information (evidence) to calculate the likelihood of an event.