Because the operator's performance affects the system's performance and reliability, we need to consider the operator's features (both capabilities and limitations) in the system design. The extended system is a model describing the interaction ... between the operators and the machine .
Zonnenshain & Harel, 2009 ( download ).
In simple systems, such as consumer products, the users are often also the operators. Examples of such systems are personal telephones, personal computers, consumer products, etc. However, in complex, real systems, such as communication networks, operators are in charge of running the services, while the users consume them.
In this model, we distinguish between the user and the operator. The operators are part of the extended system, while the users are outside, getting the output from the extended system.
This distinction is important for the purpose of this guide, because the requirements from the operators' stations are essentially different from those of user interfaces.
The operator of a bus is the driver, while the users are the passengers.
Updated on 26 Mar 2016.