We conceive "operation" as a copy, as close as possible, of the prototype operation on a given net. Including:

• Information about the economic structure of the chosen (or made up) prototype,
• Usage of the regulations of operation of the prototype,
• Usage of a timetable,
• Use of a common (model-)time,
• Control of freight flows with appropriate tools,
• and some additional issues.

Operating procedures of the original are used in an adapted way in model operation too. In the DB that are:

• Train reporting procedures with occupied stations,
• Train direct procedures with more or less unoccupied stations.

For the operation the following roles must be filled:

• Several train conductors and train drivers, possibly each as one person,
• Station inspector in occupied stations,
• Train director (for train direct procedures); that role can take a station inspector,
• Chief operating officer and dispatcher respectively for larger layouts for the central control of the operation and the freight's traffic.

The model time runs faster than the real time; approved is from 2 to 6 times faster.