Modeling and simulation software is used to model and simulate a system or process for the purposes of testing or calibration. It is used in a wide variety of industrial processes and is applied in conjunction with physical simulation systems to verify expected results. There are many different types of modeling and simulation software. Choices include flight simulation software, process simulation software, electronic circuit simulation software, engine simulation software, and business process modeling (BPM) software. Typically, modeling and simulation software is designed for operating systems such as Microsoft Windows and Linux. Specialized and proprietary modeling software and simulation programs are also available. Flight simulation software is a type of modeling and simulation software that simulates the process of flying and aircraft. It is used to train pilots and flight crews in both military and civilian applications. Manufacturing process simulation software, another common type of modeling and simulation software, is used to simulate industrial processes or procedures. Manufacturing simulation software can be used also to model that various stages of building a product within a factory, and is sometimes used to train employees who operate production machinery or manufacturing equipment. Electronic circuit simulation software is a type of modeling and simulation software that is designed to emulate the behavior of electronic circuits. It can be used for educational purposes, and to assist with design and troubleshooting techniques. Robot simulation software is also used in educational settings. Students can learn how to program robots and operate robotic equipment without using actual production robots. Similarly, engine simulation software can be used to teach students how various types of engines work, what parameters affect the performance of different engines. This type of modeling and simulation software can also be used for selecting parts to improve the performance of internal combustion engines. Business process modeling (BPM) software is used to model existing business processes, perform gap analysis, and develop change requests or new specifications. BPM software is a type of modeling and simulation software that businesses can use to determine which problems to fix first. By mapping processes graphically, businesses in many different industries can benefit by using this type of modeling and simulation software.