We have developed a method and a suit of software tools which can transform a set of message sequence charts into the state transition diagrams and the executable programs for the involved objects. The basis of our method is a regular expression over a set of actions, named the regular trace. In this paper, we define the regular trace at first, and then discuss the method for producing a concrete program from the regular trace. For this purpose, we utilized the generalized finite automaton as an intermediate representation of the object, and applied some well-known algorithms in the formal language theory. At last, we report the outline of our software tools and its application example.