1. INCOSE IS 2013 Usability Group Session #1 June 25, 2013
MBSE Usability
David Lempia

2. Introductions
Name
Company
Experience with Modeling Systems

3. Agenda What is usability? What exemplars did we capture?
What libraries would you like?
Literature review
Paper Outline for Library Guideline & Usability Challenges
Authors???

5. From INCOSE IW 2011 Top 4 Hi-value use cases:
Assemble components and associated behaviors from a library of primitives to meet the mission need
Conduct a Design Review using MBSD Environment
Make assertions on current design
Define system architecture and conduct architectural analysis

6. What is Usability? A key part of human-machine interface
According to Usability.gov: measures the quality of a user's experience when interacting with a product or system whether a Web site, a software application, mobile technology, or any user-operated device … combination of factors, including:
Ease of Learning
Efficiency of Use
Memorability
Error Frequency / Severity
Satisfaction

7. What is Usability? (2) According to SEI, a usable program:
Increases individual user effectiveness
Expedites routine performance
Accelerates error-free portion of routine
Reduces impact of routine errors
Improves non-routine performance
Supports problem-solving
Facilitates Learning
Reduces impact of errors caused by lack of knowledge
Prevents mistakes
Accommodates mistakes
Reduces impact of system errors
Increases user confidence and comfort

8. Quantifying Usability (Web)
Some methods elicit typical user mental models:
Card sorting – what categories to users naturally group ideas into?
Contextual interviews – how do your users typically attempt to solve problems?
Focus groups – what is common about your users and what is divergent?
Personas – what do you think about when describing your users?

9. Quantifying Usability (Web)
Tests reveal challenges:
Have users attempt to utilize the functionality of the software
Track time to complete, mistakes, and subjective experience of the user

10. Key Heuristics (Nielsen + Shneiderman)
Strive for consistency (a big one for the language!)
Reduce short-term memory load
Recognition rather than recall
Help users recognize, diagnose, and recover from errors
Keep system status visible
Enable frequent users to use shortcuts
Design dialogs to yield closure
Match between system and real world
Permit easy reversal of actions
Language
Tool

11. Paper 1
Abstract. This paper summarizes the conclusions of the MBSE Usability Group for Five perspectives are offered with each perspective grounded by an exemplar from the authors’ practice using Model Based Systems Engineering Environments. These exemplars range from very detailed step-by-step descriptions with identification of fine-grained usability issues to system of systems simulations developed by geographically dispersed operations in a global company. Discussion of each exemplar within the Usability Group led to significant lessons learned for the team. This paper summarized the chief lessons learned during this process. Today, the process continues. In the words of Ron Lyells, “Usability is an emergent quality.”

12. Paper 1 David Lempia - Identified basic library use cases
12 Usability Challenges
Ex: It is hard to find, identify, and understand the usage of library elements in a model.
Bjorn Cole – Specialized Domains
Judy Che - Architecture
George Sawyer – Library Templates
Craig Schimmel & Ron Lyells – Architecture

13. Scope: You Will Find Yourself Designing An Agile Complex SoS
Components: Simulation Sets, Simulation Tools
A/C Pwr
A/C ECS)
Integrity
Management
Environment
ATC
A/C FMS
Sim Control
COTS Tools
Data Capture
Measures
Infrastructure evolution:
System assembly:
Component mix:
Component inventory:
Industry Assoc
Simulation Integrators
Simulation Modelers
Engineering Functions
Active
Infrastructure
Role separation: simulation developer vs simulation integrator
Architecture goals:
Simulation environment: Borrowing from agile systems, and service oriented architectures:
System comprised of reusable simulation modules, and framework rules (defined but less rigid coupling) hide simulation interface details from user
Library management defined, assigned
Persistent environment: Over time modules are added, maybe updated, different simulation systems of systems can be formed and utilized. Infrastructure defined but allowed to evolve as technology and techniques advance.
SIM Scenarios are essentially plug and play systems of simulations. The scenarios can be expanded as needed, or simplified as needed.
Passive
SIM Scenario 1
SIM Scenario 2
SIM Scenario 3
Rules
Object Model Templates
Application Protocols
Interface Specifications
Standards: DIS IEEE , HLA IEEE
SIM API
roughly…
‘90s
‘2000s
‘10s

14. What Do Non-Executable Libraries Offer?
“Best in Class Algorithms”
What does this mean in SysML?
Rather than high-performance algorithms, models that are well-formed to support high-performance algorithms as data objects
Aids to making descriptive models descriptive
For users - where are the semantic zoom points?
E.g., in propulsion: tanks at thrusters at all levels, maybe valves not until one or two levels of depth
How should the model elements lead the user?
In viewing?
In updating?
In composing?
The key to descriptive models is that they capture and can regenerate new presentations of the implicit interconnections between multiple descriptions. This makes them powerful for working with federated analyses. Like any data source for computer algorithms, descriptive models can be constructed to either aid or obstruct computational efficiencies. In SysML, models can be built where it is easy to find related properties (via containment relationships) or can require a full traversal of the model (following non-navigable associations “backward” to find all types that have a part of the type that starts the query). High-quality libraries should respect these computational needs.
For semantic zooming, a user could automatically “zoom out” (reduce detail to get an overview of what the model view is showing) or “zoom in” (add detail). To do this well, the semantics of what is “high level” versus “low level” need to be encoded. In the case of a propulsion system design, the number and overall branching approach to thrusters is important at the top level but not necessarily the implementation of the various valves.
A base model can lead to generating views, be updated, or be composed (along with other atomic functions). A top-class library should be able to guide the user in performing each of these atomic functions.

15. Example – Customizing MagicDraw to express library in domain view

16. Vehicle Model Architecture
High-level modular structure for dynamic vehicle modeling
Key vehicle subsystems are represented as distinct elements
Subsystem connections specified through well-defined interfaces
Signals distributed to subsystems via defined bus structure
Structure & interface are fixed, model content is not
Simulink implementation of the Vehicle Model Architecture or VMA.
At a high level the VMA is a modular structure created for dynamic modeling of vehicle systems
The vehicle itself is broken down into a number of key subsystems which are represented as distinct elements
The connections between these subsystems are specified through a set of well-defined interface signals
The VMA itself is simply modeling framework where the structure and interfaces of the model are defined, but the actual model content is left up to the user.
This framework can be populated with component models of varying degrees of fidelity from a variety of sources depending the particular modeling objectives.
And as long as the interfaces comply with the VMA Standard, the model can have 'plug-n- play' compatibility.
Creating models that fit the common structure makes it easier to share and re-use models
These are the key features of the VMA that make it suitable for integrated control development.

17. Use Case Build domain models – Plant and Controls for each subsystem
Create re-usable libraries of component models with varying levels of fidelity
Integrate appropriate components to build up vehicle system model based on a vehicle model architecture – based on desired analysis
Use Variant Management to configure model selection and auto-wire models together
Transmission
Engine
Driveline
Electrical
Chassis
Plnt Ctrl Lo
Med
High
8-Nov-18 17 17

18. Possible Starting Points for Creating a New or Adapted SysML System Model
Blank model
No support beyond the tool capabilities
Relies entirely on model expertise
Problem example models
Good for explaining model concepts
Often not the best choice for a large, complex model development
Generic system model template
Can provide a generalized model usable in many different domains
Can provide significant infrastructure
Domain-specific module template
Advantages of the generic template plus additional domain infrastructure

19. Inclusion of “Pro-Forma” Examples for Correct Usage of Model Elements and Diagrams

20. Takeaways from IW 2013

21. Recommendations: The User Experience
Understand libraries as a crucial corporate asset.
Make exemplars of correct usage available in templates to streamline training and work (Put the best at people’s fingertips.)
Best Practices / Process examples
Example models
Generic
Domain-Specific
Best of class algorithms
Design the user experience.
Understand your users. (Most users will not be modeling geeks!)
Keep it simple
Support flow
Make it “write once” for the modeler
Create an immersive environment for users
As if it was a multi-player game (Because it is!)

22. Recommendations: Power Tools
For trade studies:
Support Model Variants
Support Parameter Sets
Representational Power
Support Rich Objects
Support Architecture & Design Patterns
Create an end user programming environment
Enhance modeling efficiency by supporting macros.
Bring power to programs with abstract binding capabilities.
Allow objects to tailor themselves when placed.
Make it as easy to use as a spreadsheet

23. Recommendations: Implement Service Oriented Architecture
Vehicle Model Architecture at Ford Motor Company
REAL Runtime Architecture at Honeywell
Similarities suggest using a SOA Architecture
Separate the interface code from model code
Different roles for engineers who model vs. integrate environment
Different locations in library for models vs. integration code
Develop Standard Interface Protocols
Support:
Collaboration
Plug & Play, Sharing, Re-use
Mashups

24. Recommendations: Supporting Collaboration
Immersive Multi-Modeler Environment
Shared awareness
Supporting spiral of meaning
Dialog about applying modeling during projects
Dialog about library objects
New insights into library components
Emerging architectural & design patterns
Dialog happens inside the modeling environment

25. INCOSE IS 2013 Usability Group Session #2 June 26, 2013
MBSE Usability
David Lempia

26. Introductions
Name
Company
Experience with Modeling Systems

27. Brainstorm Identify a set of desired re-usable library objects
If you could start your systems model with any library building blocks, what would you want?
Write 3-5 ideas down on a sheet of paper
In turn, share 1 new idea with the group or pass

28. Session 2 Wednesday Review Literature (Reusable Asset Specification)
Create Library Guide Paper Outline
Identify Interested Authors – Assign a section of the paper

29. Papers
Reusable Asset Specification, OMG Available Specification, Version 2.2, Nov 2005
Evolution and Composition of Reusable Assets in Product-Line Architectures: A Case Study, Jan Bosch
Metamodeling for Requirements Reuse, Oscar Lopez
Building Reusable Testing Assets for a Product Line, John D. McGregor
A Model for Effective Asset Re-use in Software Projects, Abhay Joshi

30. RAS

31. A model for effective Asset Re-use in Software Projects

32. Paper Outline 1.0 Introduction 2.0 What is a system library?
2.1 Meta Data Needed to Support Libraries
Solution
Interface (Limit external relationships to these elements)
Variants (Items that can change during usage)
Include another library element
Change a path
Change a variable
Common (Items that can not change during usage)
Dependencies to other library elements

33. Paper Outline 2.2 Meta Data Needed to Support Libraries (Continued)
Dependencies to other library elements
Classification of library element
Usage (How/Where can I use this library?)
Change History
2.3 Industry Needs (example desired libraries)

34. Paper Outline
3.0 Best Practices for Creating, Sharing and Using Libraries
Have a Suggestive Interface
Exploit Metaphors
Make Dependencies Explicit
Build in Variation
Apply Configuration Control
Provide Affordances
4.0 Usability Challenges
5.0 Conclusion

35. Systems Libraries to Share
Filters (lo-pass, hi-pass), Logic (and, or)
Computer resources (Intel Core 2 with 2 GB RAM)
Interface (ARINC 429, MS 1553)
Drag & Drop Pre-configure Subsystems, Environments filtered and sorted by abstraction
Catalog / pre-configured objects that can be composed into missions or scenarios
Rapid way of sketching objects, then refining until pre-defined elements can be placed into the sketch; transition from sketch to model.

36. Systems Libraries to Share
Basic hierarchy with structure and behaviors
All functions associated with SE life cycle
Creational patterns
A palette of objects with Visio-like graphic icons
A framework or template or wizard to guide the process
A library catalog – an index that is searchable and browsable
Architecture patterns and templates
Gang of 4 patterns

37. Systems Libraries to Share
Complete standard unit library
Constraint blocks for converting the same parameters to different forms
Variable abstraction level for components
Versions and variants; parametric models or built-in variability (CVL?)
Multi-view point domains

38. Task - How might this work?
Teams of 2-3
Pick an example from the list or select a new example
Try to capture all of the information for a reuse library element. What would it look like? What SysML elements would you use? Draw pictures, create tables, document usage.
Example, Lo-Pass Filter Solution
Interface – Signal in, Signal out, Reset
Variant – Time Constant
Include another library element - None
Change a path - None
Change a variable – Time Constant
Common
Activity Diagram
Etc.

39. Task – Paper Outline Who is interested in working on the paper?
Are you interested in a specific section?

40. Thank You for your Help