OMG SysML v. 1.4 Minor Revision Change Summary:
As opposed to the OMG SysML v. 1.3 minor revision, which introduced major changes to Physical Flows (see Critical Comment in the SysML FAQ: What’s new in OMG SysML 1.3?), the OMG SysML v. 1.4 minor revision includes only minor changes to the language.
  • Improved support for opposition hierarchies: Support for references to nested Parts in composition hierarchies. Add Bound Reference to specify connected properties that constrained by the same type or value.
  • Added Element Group to organize constructs without Package semantics. (Element Group is a drawing convenience without well-defined semantics.).
  • Enhanced View and Viewpoint constructs.
  • Added notations for inherited features, behavior compartments, and Port features.
  • Added non-normative Quantity and Unit (QUDV) model libraries compatible with ISO 80000-1.
  • Various updates to abstract syntax, concrete syntax to improve model interchange capabilities.
Unsubstantiated Claims:
  • Improved OMG SysML diagram interchange capability
Critical Commentary:
Perhaps the OMG v. 1.4 Revision Task Force (RTF) attempted to compensate for the Physical Flow scope creep in OMG v. 1.3 by ensuring that OMG v. 1.4 included only bona fide minor revisions. However, they appear to have overcompensated, since many of minor revisions in OMG v. 1.4 are poorly defined or non-normative.
You can download the OMG SysML v. 1.4 specification, as well as specifications for previous versions, from the SysML Specifications page.