The challenge of model checking of isolated software components becomes more and more relevant with the boom of component-oriented technologies [20]. An important issue here is how to verify an open model representing an isolated software component (also referred as the missing environment problem in [17]). In this paper, we propose on-the-fly simulation of the component environment to address the issue. We employ behavior protocols [18] and a system coordinating two model checkers: Java PathFinder [4] and BPChecker [15]. This approach allows us to enclose the model represent- ing the behavior of a given component and consequently to exhaustively verify the model. Our solution was implemented as the Carmen tool [1]. We demonstrate scalability of our approach on real-life examples and show that, in comparison with the COMBAT model checker [17], we bring better performance, and also exhaustive and correct verification.