Identify exchange items such as requests, data packets, messages, and signals early on and use the SysML ItemFlow as often as you can wherever you! Adopt a signal processing mindset throughout your modelling (systems thinking).
This is perhaps the single most important unifying principle behind the Webel approach to SysML and the Webel Best Practices for SysML. This is the universal glue that will will help bind and unifying all other aspects of your SysML models !
It is also strongly supported by the Webel Parsing Analysis recipe for SysML®, where possible exchange items are identified early on from natural language domain source documents and their graphics, photos, and other illustrations. There are heaps of examples of this approach throughout this site.
The contrived Association names used here are merely to indicate the connected blocks for pedagogical reasons, rather than more descriptive names:
The focus BDD shown at the bottom is actually not typical of a Webel-style focus BDD as used on real projects, it just some of the things one might include:Ever "lost" your ItemFlows but you know they are there somewhere?