The American rational software corporation (presently 1 section of IBM), the portable ? ? various experiences and expert knowledge of the enterprise people who come, adopting the practice to early object direction based software development, the development methodology which it collected as inclusive system (software development process), or the process product which supports that.

The feature of RUP designates the use case as base point of development and (use case drive), sets basic structure of the software which is developed to early stage (the architecture center),like the waterfall, it is not to suppose the finished product of complete shape from beginning, important function and big function of risk it is constructed to the use case unit (repetitive opening departure) is thing and the like. In addition, the process of RUP customizing in every organization, and project is formed it utilizes (customization possibility) as a thing, being not to be one process, also the "process framework" is called.

The nineties beginning, various object direction development methodologies having been flooded and being confused. Then at that time,of the Booch method which is powerful in these methodologies (Grady Booch) with, ????? run baud of OMT method (James E. Rumbaugh) agreeing to standardizing mutual methodology, from 1994 it started job at the rational corporation, it collected the methodology "Unified Method V0.8 which" includes process and notation in next year.

(Ivar Jacobson) participated here, could adopt that development life cycle system "Objectory approach" substantially, "Rational Objectory Process 4.0" was announced in 1996. At this time, process and separation of notation were done, but (notationwas expandedto the process where UML becomes), after that expert knowledge such as management, design, test and project management of request being installed, the whole life cycle of software development supports in process, was announced in 1998 as "Rational Unified Process 5.0" from the rational corporation.

As for RUP presently version rise is advanced, the expansion which was called adaptation to the small-scale development Web, J2EEand NET tocorrespondence etc. with the super set conversion of other things and various Agile software developments is done.