What is a ROOM Diagram?
Developed by ObjecTime (which was later acquired by Rational Software), ROOM stands for real-time object-oriented modeling.
The actor or the software machine is the central component of the ROOM method. ROOM diagrams illustrate both the structural and behavior aspects of the actor. You can use ROOM diagrams in conjunction with the Unified Modeling Language (UML).

Structural Diagrams
ROOM structural diagrams illustrate actors and interfaces between actors.
