This paper introduces a method for building a real-time simulation model with adjustable user-selected parameters. The proposed design process model consists of eight steps with four decision points. Parameterization is a technique enabling real-time simulation with different combinations of parameters. Currently, there is no unique way to incorporate user input and switch between model combinations. The proposed method is presented in the form of a flowchart. Based on the data, a 3D design of the model was constructed. Two alternative approaches were introduced to construct a parameterized real-time simulation model with user inputs. The approach used was selected based on the number of parameterized specifications. The feasibility of each case was analyzed analytically and by simulation. Finally, a version of the model was selected based on the given initial requirements. To illustrate the developed approach, an excavator model was selected for parameterization. In the excavator model, two parts are considered to have adjustable parameters: the bucket and the hydraulics. Each part has three options that can be selected by users. The approach enables easy adaptability of user-generated parameter inputs, thus permitting evaluation of multiple scenarios, while simultaneously maintaining realistic representation.