For a simple applet, we can put all the methods containing the methimetical and physical functions in this module. In this case, the AppletLogic module contains both the core data and the functioanlity for the data updating. In a complicated applet, however, it is desirable to have a saperate module for the computations. This module, we call it the Algorithm module, has the computation functionality in it and may contain a number of different algorithms. At different time, one algorithm is appropriate for the simulation task. And the applet user can switch among the algorithm classes on the fly. We named this module the Algorithm module.

Since the microelectronics and semiconductor simulation is a complicated process, providing different algorithms sometime and applet executions modes will assist the applet program development and help the applet user in their active learning. The switching among the different algorithms and executions modes is facilitated by the dynamic binding. The applet programmer can write several different algorith classes and have them all inherite the superclass in this Algorithm module, which is the Strategy.java class.