The term “object oriented” spread in the last decade and a half, throughout many fields of computing, including the analysis and design of information systems (IS). The use of the OO approach began in the early 1970s in fields such as computers architecture, operating systems, and artificial intelligence. But the main field to which the approach penetrated was programming languages, beginning with Simula and then with Smalltalk. Some years passed by until the approach became popular in the programming field. Reasons for the vigorous penetration of the approach include the emergence of the windows-based graphical interfaces technology, the desire to economize development costs by reusing existing software, and the transition from centralized computing to distributed- and Internet-based computing. As aforesaid, the approach penetrated into other fields of computing due to its success in the field of programming, including the field of analysis and design of IS.