This post is the second part of the blog post series about the changes of SysML 1.5. The biggest novelty in SysML 1.5 is only visible on the second view. If you do not use the new feature, you will not recognize it. Since version 1.0 SysML provides the model element Requirement to model text-based requirements, it has only two properties: one to specify the ID of the requirement and another one for the requirement text. SysML intends that modelers can define additional...

How to relate requirements and architecture on different abstraction levels The SYSMOD zigzag pattern describes the different levels of abstractions and the relationship between requirements and architecture. [caption id="attachment_135" align="aligncenter" width="584" caption="The SYSMOD-Zigzag-Pattern"][/caption] Your system requirements do not start at the very top of the levels, i.e. they already include some technical decisions. The base architecture is the architecture one level above your top level requirements. The following figure shows a simple base architecture of a forest fire detection system (FFDS). [caption id="attachment_406" align="aligncenter" width="469"...

I've just found this question in a sysml discussion forum: Is it really not possible to place requirements objects on an Activity, State Machine, or several other similar behavioral diagrams? Yes, it is not allowed to put requirement elements on a state machine or activity diagram. Since it is essential to show such cross cutting relationships SysML provides the callout notation. A comment symbol is attached to the state or action or to any other element in the state machine/activity diagram. The...