Introduction to Model Based
Systems Engineering (MBSE)
Energy Tech 2016
L. Mark Walker
(28 November 2016)
Topics
• What is a Model?
• Overview of Model Based Systems Engineering (MBSE)
• The Systems Modeling Language (SysML)
• Object Oriented SE Method (OOSEM)
• Personnel & Training
• Tools & Examples
• Conclusions/Recommendations
What is a Model & a Simulation?
• INCOSE SE Handbook (Fourth Edition):
• “The term “model’ has many definitions but generally refers
to an abstraction or representation of a system, entity,
phenomenon, or process of interest (DoD 5000.59, 2007)…”
• “…in the context of SE, a model that represents a system
and its environment is of particular importance to the
systems engineer who must analyze, specify, design and
verify systems, as well as share information with other
stakeholders.
• “… simulations (versus Models) is the implementation of a
model (or models) in a specific environment that allows the
model’s execution (or use) over time. In general, simulations
provide a means for analyzing complex dynamic behavior of
systems, software, hardware, people and physical
phenomena….”
Static Models & Dynamic Simulations
Model Based Systems Engineering (MBSE)
• Formalized application of modeling to support system
requirements, design, analysis, verification and validation
activities
• Beginning in the conceptual design phase and continuing
throughout development and later life cycle phases
• (“A Practical Guide to SysML”)
Model Based SE (MBSE)
Practices for Developing Systems
MBSE Supports:
• Customer Needs
• Operational Concepts
• Specifications/Requirements
• System design/architectures
• Interfaces & Models
• Analysis & Trade-off
• Test plans/procedures
• Life Cycle Support
Moving from Document Centric to Computer based Model Centric
AirplaneATC Pilot
Request to proceed
Authorize
Power-up
Initiate power-up
Direct taxiway
Report Status
Executed cmds
Initiate Taxi
Past Future
MBSE
Interrelationship that Establish
MBSE, UML, SysML & OOSEM
OO
Concept
Fundamental SE Best
PracticesUML (Universal Modeling
Language)/OMG
SW Engineering: e.g.
ISO 12207, & OOA/D &
Agile SW Concepts
SE Engineering:
e.g. ISO 15288 &
Agile SE
Concepts)
Guides, etc. (e.g.
INCOSE SE
Handbook,
SEBOK, etc.
SysML (System Modeling
Language)/OMG
OOSEM (Method)
Fundamental SW
Best Practices
OVERVIEW OF MBSE:
THE FOUR MBSE ESSENTIALS
3. Tools
E.g. Magic
Draw
Customer Needs SE Models & Products
4. Trained
MBSE
Experts
2. Language
Specifications
E.g. SysML,
UPDM, UAF
1. Methods
E.g. OOSEM
MBSE
L. Mark Walker
INCOSE IW10 MBSE Workshop- Mark Sampson page 8
Integrated Systems Engineering Vision
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Dry Pavement Braking Distance at
60 MPH : 110 ft.
Thermal/
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Minimum Turn Radius: 24 ft.
Dry Pavement Braking Distance at
60 MPH: 110 ft. 90 ftFigure not include in SE Vision
Modeling Representations
Depend on the Audience, i.e. who is the model for:
Engineers, managers, support personnel, training, etc.
will require difference model representations and
information
The Scope of representations can be a few to many (e.g.
DoDAF 2 has 52 views for one system over its life cycle
The phase of a development or upgrade needs different
and/or tailored views within the model
Models evolve/change during life cycle phases
The level of complexity varies and is dependent of the need
for information by the audience
The supporting information must be provided to the level of
detail needed by the audience
I.E.: Based on the Purpose, Scope, Objectives and Audience
Evolution Life Cycle of Models, Architecture, etc.
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1
2
3
OVERVIEW OF OOSEM
PROCESSES
OBJECT-ORIENTED SE METHOD
• “Top-down, scenario-driven process that uses
SysML to support the analysis, specification, design
and verification of systems”
– From “A Practical Guide to SysML, Third Edition: The Systems
Modeling Language”, by Friedenthal, Moore, Steiner, Copyright
2015
• Leverages Object-Oriented Analysis and Design
(OOA/D) with Model-Based and Fundamental SE
methods to help analyze, architect, and engineer
flexible and extensible systems that accommodate
evolving technologies and changing operational
needs & requirements
• Facilitates integration with object-oriented software
development, hardware development, and
verification and validation (V&V)/testing
Systems Requirements & Design Activities & Models - OOSEM
Synthesize
Allocated
Architecture
Define
System
Requirements
Define
Logical
ArchitectureOptimize &
Evaluate
Alternatives
Support
Validation &
Verification
Analyze
Needs
Major SE Development Activities
Fundamental SE Development Sub-Activities
Parametric DiagTrade StudyArchitecture Views
Test CasesUser StoriesVerification & TestProcedures
Causal AnalysisMission Use Cases/ScenariosEnterprise ModelMission Concept Document
System Use Cases/ScenariosElaborated ContextSystem Concept DocumentReqts-Architecture Mapping
Logical DecompositionLogical ScenariosLogical Subsystems
Node DiagramHW, SW, Data ArchSystem Deployment
Manage
Requirements
Reqt’sDiagram& Tables
Figure 17.2 (Object Oriented Systems Engineering Method)
Figure 17.2
*Reference: “A Practical Guide to SysML”, second edition
FIGURE 17.5 (ANALYZE STAKEHOLDER NEEDS ACTIVITY)
Figure 17.5
*Reference: “A Practical Guide to SysML”, second edition
Tailoring the OOSEM method
OOSEM can be tailored to meet project objectives and
constraints (i.e. time and money available)
Tailoring is very dependent on the domain and
environment for the system, audience, etc.
Tailoring involves selecting the appropriate level of rigor
to apply to each of the OOSEM activities
Selecting the activities and their ordering
Selecting the artifacts to generate
Selecting the level of detail
Feedback and iterations to develop the Optimum solution
based on current & potential future information and
knowledge
16
SYSTEM MODELING LANGUAGE
(OMG)
SysML DIAGRAMS
SysML
Diagram
Parametrics
New
Behavioral Structural
ActivityState
MachineBlock
DefinitionInternalBlock
Sequence
Package
Spec-Oriented
Un-changed
Modified
UseCase
Reqts
Key
act sd stm uc req par bdd ibd pkg
18
First Stage, Develop Stakeholders’
System UCs, Scenarios & Sequence Diagrams
System Use Cases are a SysMLTM “Spec Oriented” (Requirements) Diagram.
Virtually all SysML and other Architecture diagrams/Models are Derived From & Map To Stakeholders’ System Use Case Diagrams
Copyright © 2014 by Loren M. Walker.
MBSE/SysML Tools
• Many tools support MBSE but vary in their
implementation, look and feel, etc.
• But those that support MBSE must meet the OMG’s SysML
Specifications
• The tools are computer based tools that apply the
specification and associated rules, views, etc.
• The tools capture and manage the models’ views
contents, view and element relationships and all
associated data & information for all views/elements in
One Data Base
• Most advanced tools include ability to interface and/or
share data with other tools that provide further
capabilities
• MBSE SE’s must be trained on these tools to be effective
Integrated Tools
Project Management
CM
/DM
Pro
duct
Data
Manag
em
ent
Requir
em
ents
Manag
em
ent
Engin
eering
Perf
orm
ance A
naly
sis
Verification &
Valid
ation/P
ara
metr
ic
Math
, etc
.
SoS/UAF/DoDAF/ Business Process Modeling/
Unified Profile for DoDAF and MODAF (UPDM)
etc.)
System Modeling
SysML
Software Modeling
UML 2.0
Hardware Modeling
VHDL, CAD, ..
Specia
lty E
ng
ineering
Analy
sis
Personnel Training Required
As shown in the first diagram:
Trained System Engineers in MBSE are Essential
This Training includes:
• Fundamental Systems Engineering Life Cycle Processes
• Includes experience is system developments &
deployments
• MBSE, SysML and OOSEM Training
• SysML Based Tools Training
• Team work with other trained SE, SW and other design
and support professionals
• The ability to work with Operational Customers to
develop System Use Cases, Scenarios, Operational
Concepts, Models, etc. to initiate the development
process
Summary/Conclusions
MBSE is an implementation of Systems and Software
specifications, methods, tools and trained personnel
MBSE integrates Systems/Software Best Practices based on
Guides, Handbooks, Specifications, Research
SysML Computer based Tools are essential with One Data Base
for all views, relationships, information for Models,
architecture, elements, requirements, users/operators, etc.
Implementation of MBSE must meet customer and engineering
domain requirements
e.g. Military, Industries, Customers, Engineering disciplines
Expertise and experience is Essential- i.e. Trained Personnel
Provides Rapid (Agile) Reaction to Life Cycle Changes & Reqts
Applicable to SoS and System Analysis, Upgrades,
Development
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