SysML Language Architecture Clause Samples

SysML Language Architecture. SysML reuses a subset of UML2 and provides additional extensions needed to address requirements in the UML for Systems Engineering RFP. The SysML specification documents the language architecture in terms of the parts of UML2 that are reused and the extensions to UML2. The SysML language reuses and extends many of the packages from UML. The set of UML meta- classes to be reused are merged into a single meta-model package, UML4SysML. Some UML packages are not being reused, since they are not considered essential for systems engineering applications. The SysML profile specifies the extensions to UML. It references the UML4SysML package, thus importing all the meta-classes into SysML that are either reused as-is from UML or extended in SysML. The semantics of UML profiles ensure that when a user model “strictly” applies the SysML profile, only the UML meta-classes referenced by SysML are available to the user of that model. If the profile is not “strictly” applied, then additional UML meta-classes which were not explicitly referenced may also be available. The SysML profile also imports the Standard Profile L1 from UML to make use of its stereotypes. SysML stereotypes define new modeling constructs by extending existing UML 2 constructs with new properties and constraints. SysML diagram extensions define new diagram notations that supplement diagram notations reused from UML2. SysML model libraries describe specialized model elements that are available for reuse. The SysML user model is created by instantiating the meta-classes and applying the stereotypes specified in the SysML profile and sub-classing the model elements in the SysML model library.