Abstract: Computer software allows for users to easily construct and simulate operation of cause models in which elements interact as parts of a system. A graphical user interface (GUI) allows a user to place cause model elements and connect the elements with relationships that allow changes in one element to cause changes in one or more other elements. The graphical user interface may also be used to configure characteristics of the elements and/or the relationships. The computer software allows simulation of performance of the cause model by perturbation of levels in the elements, or by other setting of initial conditions. The software may allow for various feedback of the model during simulation. Levels of the elements or of the intensity of interactions through relationships may be communicated by the software to the user during a cause model simulation, in any of a variety of ways.