1. A computer program, encoded on a computer-readable recording medium, which causes a computer to transform a UML design model including protocol state diagrams and activity diagrams of classes into a stochastic performance evaluation model, the computer program causing the computer to function as: means for transforming a static call graph into a syntax tree having a binary tree structure; means for transforming each of the protocol state diagrams into a stochastic process algebraic form; means for transforming each of the activity diagrams into a stochastic process algebraic form; means for obtaining a stochastic process algebraic form of each of the classes by merging the process algebraic form of the protocol state diagram, and the stochastic process algebraic form of the activity diagram; and means for obtaining a stochastic algebraic form of a whole system from the syntax tree, and from the stochastic process algebraic forms of the classes.