The first step to building a simulation model of a real system is to gather data associated with that system.
Data can be in either symbolic or numeric form.
Typically, numerical data are obtained using either physical sensors or human sensors. Nominal data are obtained from humans using interviewing methods or knowledge acquisition techniqies developed to obtain qualitative knowledge. The model usually contain parameters which must be estimated. Models must be converted to algorithums to run on a digital computer. Parallel processing and simulation section Thin Film Process Simulator .