Internal Block Diagrams (IBD) allow for the elaboration on a given SysML Blocks. Each IBD is bound to and represents a particular Block. It explains more information about valid configurations block instances have to uphold. The are used to convey:

• Show Block Reference Properties bound to the things they reference.
• Connectors between properties internal to the block
• Connectors to outside elements, via ports
• The types of matter/information (’Item Flows’) that are associated with these connections

IBDs are contextualized by Block Definition Diagram s. It’s a common practice in SysML to have a tick-tock approach wherein BDDs and IBDs are used in an alternating fashion to “zoom in” on particular aspects of a system (enabling Decomposition Understanding).

See how BDDs contextualize IBDs.

Examples borrowed from ‘A Practical Guide to SysML’

Other Sources

A Practical Guide to SysML - book

Related Notes

SysML

SysML Blocks

Block Definition Diagram

Decomposition Understanding