Simulation and modeling - Old Questions

a. System, boundary and system environment

• A system is defined as a collection of object join in some regular interaction or interdependency for achievement of a common goal. We can also define a system as organized set of inter-related idea or principles. All system have input, output and feedback and maintain a basic level of equilibrium.
• A system boundary is the line that separate the system and its environment.
• The external components which interact with the system and produce necessary changes are said to constitute the system environment. In modeling systems, it is necessary to decide on the boundary between the system and its environment. This
  
  

b. Real time simulation

Real-time simulation refers to a computer model of a physical system that can execute at the same rate as actual "wall clock" time. In other words, the computer model runs at the same rate as the actual physical system.

For example, if a tank takes 10 minutes to fill in the real-world, the simulation would take 10 minutes as well. Real-time simulation occurs commonly in computer gaming, but also is important in the industrial market for operator training and off-line controller tuning.