We present a simple, effective and original way to make the most of complementarity among several Knowledge Representation and Reasoning approaches. The principle is to convey knowledge from one approach to another, using a set of transition rules. So, based on these rules, we obtain a system, that we called Transitions-Based System, composed by several KR&R approaches where they and their tools can be used together, on one hand for representing knowledge with then a rich expressive power and on the other hand for reasoning in a large and complex manner. To illustrate a such system, we focus on the case composed by the synergistic use of OWL, Conceptual Graphs and UML.