Webel SE: pragmatic tool-friendly functional analysis: 2-level drill-down from a single Use Case via a «scenario» Activity with allocation to «logical» subsystems first then crossing to the «design» Blocks zone.

Gallery
Tutorial
[STUB] TRAIL: Webel's ultimate guide to simplified yet adequate pragmatic systems engineering with functional analysis in SysMLv1 for smaller scale MBSE projects in the MagicDraw/Cameo/CATIA Magic tools
Section
Topic level
INTERMEDIATE
Keywords
Slide kind
diagram
SysML Activity Diagram
SysML Block Definition Diagram (BDD)
SysML Internal Block Diagram (IBD)
SysML Package Diagram
SysML UseCase Diagram

A very simple functional analysis breakdown with every step all in one place and with concise Webel naming conventions, in one combined diagram!

We follow one scenario Activity serving a UseCase down through one level of logical «whitebox» subsystems then down to the design (and implementation level) Blocks.

Click on the image to view it full size
Please be sure to inspect also the Policy Notes for the pragmatic Webel SE recipe linked below. They are also collated here:
[STUB] TRAIL: Webel's ultimate guide to simplified yet adequate pragmatic systems engineering with functional analysis in SysMLv1 for smaller scale MBSE projects in the MagicDraw/Cameo/CATIA Magic tools
Up next
Notes
[CONVENTION, MODELLING, TIP] Webel: SysML for MBSE: The frequent recommendation that each UseCase have at least one "primary" scenario is a very useful and highly recommended CONVENTION (only). But it is not actually enforced by the SysML1.7 or UML2.5.1 metamodels or specifications.
[MODELLING]{INFORMATIVE} Webel: SysMLv1: Overview of annotated Diagram Slides and Note pages related to UseCases and their combination with a System (of interest), SystemContext, and drill-down to scenario Sequence Diagrams (Interactions) and Activity Diagrams.
[CONVENTION, MODELLING, OPTION, TIP]{INFORMATIVE} SysMLv1: UseCase scenario representations: On use of Activity Diagrams with swimlanes and/or Sequence Diagrams (Interactions): Actor or block-based custom «actor» on 1st (typically left) Lifeline/Swimlane, System/Subsystem on 2nd Lifeline/Swimlane
[MODELLING, OPTION, TIP]{INFORMATIVE} SysMLv1: MagicDraw/Cameo: Automated creation of usage-level allocation swimlanes in SysML Activity Diagrams for part properties of a Block. EXAMPLE: A UseCase scenario within a SystemContext as UseCase ‘subject’.
[GOTCHA, MODELLING, OPTION, TIP, WARNING]{INFORMATIVE} SysMLv1: MagicDraw/Cameo: INTRINSIC GOTCHA: Care must be taken with ownership of Activities used as UseCase scenarios vs the ‘subject’ of the UseCase. Make sure you don’t get an Activity ‘context’ mismatch! It's up to you to manage it as intended.
[EXPLANATION, GOTCHA, MODELLING]{INFORMATIVE} Webel: SysML: SE: Terminology: '«logical» handler' is used for a specific kind of «logical» subsystem (aka 'conceptual subsystem') that is a SPECIFIC collaboration of parts that handle one Activity usage in a higher level «whitebox» Activity.
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysML: SE: Naming convention: '0' used for a Package/Model name indicates a zone dedicated to a formal systems engineering breakdown (functional analysis, blackbox, whitebox, logical vs design or implementation etc.)
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysML: SE: Naming convention: «whitebox»: A '$' prefix indicates a «logical» system, «logical» subsystem (aka conceptual subsystem) or «logical» handler Block (which is a more specific form of «logical» subsystems Block).
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysML: SE: A functional analysis «whitebox» Activity may have swimlanes that Allocate to logical subsystems (logical handlers) within the 'problem' zone or to design/implementation level blocks.
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysMLv1: Functional analysis (isolation of white-box Activities identified via «blackbox» scenario Activities of UseCases). Recommend custom stereotype them. Candidate: «whitebox» (or a recommended SE methodology stereotype).
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysML: SE: «blackbox»: The custom Stereotype keyword «scenario» indicates a Behavior (Interaction as Sequence Diagram or Activity) that Refines a top-level UseCase within the 'problem' zone.
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysML: SE: Stereotype keyword convention: BY DEFINITION HERE «blackbox» and «whitebox» refer specifically to the 'problem' zone and NEVER the 'solution' zone (as opposed to more general uses of the terms 'black-box' and 'white-box').
[CONVENTION, MODELLING, NAMING, TIP]{RECOMMENDED} Webel: SysML: Use concise Package and Model naming to provide "context aware" owner paths that reflect a systems engineering strategy. Extremely so-called "human friendly" verbose Package/Model names with spaces DO NOT make the model easier to understand!
[CONVENTION, MODELLING, OPTION, TIP]{INFORMATIVE} SysMLv1: UseCase scenario representations: On use of Activity Diagrams with swimlanes and/or Sequence Diagrams (Interactions): Actor or block-based custom «actor» on 1st (typically left) Lifeline/Swimlane, System/Subsystem on 2nd Lifeline/Swimlane
[ASSERTION, TOOL] SysML: The «system», «subsystem», «external», «domain» and «system context» keywords are for "user defined" block Stereotypes (they are not part of core SysML); they are supported in MagicDraw/Cameo as Non-Normative Extensions.
[CONVENTION, FEATURE, MODELLING, OPTION, TIP, TOOL]{INFORMATIVE} SysMLv1: MagicDraw/Cameo: Having a SystemContext as the 'subject' of each main UseCase plays nicely with the feature for automated creation of usage-level allocation swimlanes in SysML Activity Diagrams for part properties. But it's not the only way.
Snippets (quotes/extracts)
Visit also
Visit also (backlinks)
Related slides (includes other tutorials)
Related slides (backlinks, includes other tutorials)