Next to the concept the objects (AOO) and guided project had appeared innumerable proposals of models of guided analysis the objects (POO). This amount of proposals generated quarrels on which model would be optimum (AOO or POO). In addition, it was difficult to occur a good agreement between development teams, for rare using the same models of development OO. It had then a proposal of creation of a unified model enters three (3) great names of the area of software engineering, James Rumbaugh, Grady Booch and Ivar Jacobson.
As result of this union appeared Unified Modeling Language (UML), serving as a norm it enters the companies of software development. However the UML served as auxiliadora tool in the stages of the software engineering and not as a mold (skeleton) to be followed in the development of systems OO. During some years passed of the sprouting of the UML, the same creators had developed Processo Unificado (PU). This yes started to serve as a model to be followed during the stages of development of great systems OO. The PU considered the iterative and incremental model, leaving software with more robust in the measure where the time passes. Currently the PU and the UML are widely used in set for desenvolvedoras companies of software OO.
The iterative and incremental model of the PU must be adapted to satisfy to the specific necessities of the project. 3-Principle 3,1 – Directed for use cases They indicate the functionalities to be fulfilled for the system, being able to generate a functionality more than. They assist in the construction of the project and analysis model. Later, in the stage of tests. With this we can perceive the expression ‘ ‘ directed for cases of uso’ ‘ , therefore it is present in all the stages of software development.