  Knowledge organization, infrastructure, and knowledge-based activities are
all subjects that help in the creation of business strategies for the new
enterprise. In this paper, the first basics of knowledge-based systems are
studied. Practical issues and challenges of Knowledge Management (KM)
implementations are then illustrated. Finally, a comparison of different
knowledge-based projects is presented along with abstracted information on
their implementation, techniques, and results. Most of these projects are in
the field of medical science. Based on our study and evaluation of different KM
projects, we conclude that KM is being used in every science, industry, and
business. But its importance in medical science and assisted living projects
are highlighted nowadays with the most of research institutes. Most medical
centers are interested in using knowledge-based services like portals and
learning techniques of knowledge for their future innovations and supports.
