
Note that logical elements can be either system elements that contain some combination of hardware, software, people and information, or can be workers. A worker is a human that is part of the system at the level above, and thus is not represented as an actor. For example, if my enterprise (level 0) system is an aircraft, we would likely consider the pilot to be inside the system of the aircraft, thus the pilot does not appear as an actor at level
So the pilot could come out as a
MDSD Step 10: Creating element context diagrams
As logical elements are determined, it helps to create context diagrams to show these elements and their relationships to actors, and to each other. To create a context diagram for a level 1 system element, we draw the element, along with all of other elements with which it interacts. The elements can be one of three possible types:
Actors, which also appear on the level 0 context diagram
Other level 1 system elements
Level 1 workers
Context diagrams can be created for each logical element. Like an enterprise context diagram, these show a certain element, its actors, and their I/O entities. When drawn in a UML or SysML modeling tool, these context diagrams also serve as collecting points for the operations that will be derived for these elements (Figure
With an initial cut at the logical elements for this model level or level of decomposition, we are ready to proceed to the realization of the operations.
2Currently no modeling tool handles this issue well. Several workarounds are
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