"knowledge management" isnt a system per se its more of a philosophy or gradiose title for basically business analysts
business analysts look at the data your company has on stuff like its customers, calls they make, where etc, and use that to draw trends and other information from that data and can use that information to speculate on the next moves the company should make
its basically a processe of taking data thats unuseful in its raw form, processing it into information that is useful to the company and reporting on it
there are a variety of different methods and software used to do this, i cant think of any specific pieces of software - but your more likely to find the answer under the heading of Business Intelligence software than knowledge management systems which is what i am guessing you are referring to