Agent design is a complex human activity involving active and proactive modules of software that may present knowledge representation and learning aspects. In this study we review some Agent-Oriented Methodologies including extensions of object oriented and knowledge engineering methodologies. Moreover, we present a case study of a multi-agent system for requirement engineering formal specification that was designed using "the Agent Modelling Technique for Systems of BDI agent" [12]. Finally, a discussion about the use of the methodology is presented.