1. SysML v2 Usability Working Session
OMG Meeting
Reston, VA
March 21, 2017
Sanford Friedenthal
6/27/2018

2. Topics Usability Introduction & Session Overview – Sanford Friedenthal
Ideas on Usability Layering -Bertil Muth
Break
User Centered Design Approach - Tricia Lagoon
Facilitated Discussion on SysML v2 Usability Requirements
6/27/2018

3. Session Objectives & Approach
Define minimal usability requirements/criteria and supporting assessment methods for SysML v2 RFP
Increase awareness of usability concerns and approaches
Approach
Elicit inputs from modeling end users with a range of experience levels and modeling tool vendors

4. User Classes New modelers Seasoned modelers Consumers of model data
Early career and experienced systems engineers learning SysML
Seasoned modelers
System engineers with experience in modeling, comfortable with using SysML and modeling tools
Consumers of model data
Other engineering disciplines who do not use SysML modeling tools, but need to understand and interpret model information
Needs vary across lifecycle, disciplines, and application domains

5. Wikipedia https://en.wikipedia.org/wiki/Usability
Usability is the ease of use and learnability of a human-made object such as a tool or device.[1] In software engineering, usability is the degree to which a software can be used by specified consumers to achieve quantified objectives with effectiveness, efficiency, and satisfaction in a quantified context of use.[2]
6/27/2018

6. Usability Criteria Usability Criteria New Modelers Seasoned Modelers
Model Consumers
Intuitive/understandability
- Creating models
High
Medium
Low
- Interpreting models
Modeling efficiency
6/27/2018

7. MBSE Learning Obstacles
MBSE is a more rigorous/formal approach to address the inherent complexity of systems and SE methods
System complexity (e.g, layered interfaces, complex state behaviors, complex structures with assemblies and subsystems)
SE Methods must address multiple stakeholder viewpoints that span multiple requirements, multiple levels of design, across disciplines, and full lifecycle
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8. SysML Language/Tool Usability Issues
Learning obstacles
Definition/Usage (e.g., part vs block, action vs activity, ..)
Maintaining consistency across views
different kinds of behavior, structure, parametrics, requirements
Model containment tree vs product structure
Unfamiliar terminology from UML legacy and SysML (e.g., proxy port)
Functional vs geometric concepts (enclosed by versus external to)
Lack of engaging/intuitive domain-specific visualizations (i.e., boxology)
Inability to express informal ideas and refine
Ability to abstract
Productivity obstacles in model construction
Complexity of user interface
Create/update one element at a time (too many clicks)
Manual diagram layout
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9. SysML v2 Usability Focus
Model Visualization Concept
Model Construction Concepts
Language Concepts and Formalisms
6/27/2018

10. Visualization Concept
Source: C. Schreiber, J. Feingold, M. Sarrel
Browser-Based Data Presentations
Model Data
User
Contributor
System Modeler
Model Organization & Development
Pattern & Model Library Definitions
Model Customizations
Model Updates
Report Generation
Model Execution
Model Review & Comment
Predefined Reports
User-defined Views
Heavy Model User
Reviewer/Consumer
Light Model User

11. Model Construction Concept
Source: R. Williamson
Model Construction Workflow Example
[login]
Execute Analysis
Note: Iterative steps not shown
Import
Requirements
Reference
Library
Analyze
Requirements
Batch Import & Transformation
Component
Library
Select Reference Architecture Variant
Execute Analysis
Supports different classes of collaborative users (e.g., expertise, domain, life cycle)
Driven by iterative / agile workflow
Batch import, transformation & export
Broad application of patterns & reuse libraries
Textual, graphical and tabular model create, update and delete
Model ownership, baseline & version management via Model Management
Black Box/White Box Representations via Model Management
Model views & usability via Model Visualization
Requirements/Design Analysis via Model Analysis
Integrate & Configure Component Designs
Evaluate Architecture Designs
Apply Patterns
Update Baseline
Commit to Server
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12. Other Usability Concepts
Simple hierarchical lists with cross connections
Mind maps
Wiki’s
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13. SysML v2 Usability Expecations
Should SysML v2 be simple (how does this contrast  with mechanical and electrical design tools and languages)
What are examples of user friendly languages (MATLAB, Simulink,. …) and user friendly interfaces (Apple/Iphone)
How much of the usability is allocated to SysML v2 vs the tool vs the method
How can customization address  the usability needs (e.g., jargon/aliases, visuzliations, domain specific symbology, …)
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14. Usability Requirements
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15. Backup
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16. Requirement How quickly can a modeler find what they are looking for
Level of assistance when stuck
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