Holonic Multi-Agent Systems (HMAS) are a convenient way to engineer complex and open systems. In such systems, agents have to be able to self-organize to satisfy their goals. Our works focus on modeling and engineering of complex systems using a holonic organizational approach. This paper introduces the concept of capacity as the description of agents know-how. This concept allows the representation and reasoning about agents know-hows. Even more, it encourages a reusable modeling and provides agents with means to self-organize.