4.1 Introduction
Once the problem has been properly formulated and the project plan is complete, the simulation
practitioner should direct his or her attention toward defining the system that should be modeled. For
our purposes, a system is a group of components that receives inputs and delivers outputs. The components
determine how the system converts inputs to outputs. The system may exist in an environment
that could also potentially affect the inputs and outputs. The system definition and model formulation
process consists of determining:
• The system classification
• How much of the system to model
• What components and events to model
• What input data to collect
• What output data to generate with the model