Nowadays, we are surrounded by system of systems, autonomous systems, interconnected systems or distributed heterogeneous systems with an increase in architecture complexity. Keeping these systems operational is a challenge as the number of potential failures which may affect their availability also increases drastically. In order to optimize availability, maintenance activities have to be designed within the design phase of the system. Whatever the implementation choice, detection, diagnostic or prevention of failures require tests. The goal for autonomous systems also pushes towards embedded detection and prevention capabilities and thus arguing and decision making between system engineers and maintenance engineers to share solutions in their respective activities. In this presentation, we talk about the ability of a system designed with Capella to be tested, including in the maintenance phase. This means to interconnect several kinds of models representing different perspectives: System Design (MBSE), RAMS Analysis (Reliability, Availability, Maintainability and Safety) and Testability. We present how a MBSE approach with Capella can be used to initiate a testability study performed with the eXpress tool from DSI International.

1. 1
MBSE and Model-Based
Testing with Capella

2. 2
Agenda
 Context of our study
 Testability
 Definition
 Collaborative Engineering Domains
 Operational tools and modeling
 Targeted operational use case

3. 3
SPHEREA
A worldwide test solutions provider for critical systems since 1965 for all lifecycle phases,
Prototyping tool
System design
Detailed design Integration tests
System test
Production
Long-term continuity
Simulation equipment
Software integration benches
Test system on
final assembly line (FAL)
Obsolescence
management aids and
services
Maintenance test solutions
Production test benches
Integration test benches (equipment, systems)
Maintenance

4. New Evolution
Locomotive
Crusader
Self-Propelled
Howitzer
Space Operations
Vehicle (SOV)
X-33
VentureStar
AIM-9X Evolved
Sidewinder Missile
2nd Gen RLV Future Combat
Systems F-35 (JSF)
Eurofighter
TSAT Satellites
Fire Scout UAV
Comanche
Helicopter
CVN-76 Nimitz-Class
Supercarrier
DSI Has Extensive Experience on
Major Programs since 1975

5. FMECA Plus
Commercial IETMs,
TRD & TPS Generation Tools,
Custom Diagnostic Solutions,
Written Documentation
STAGE
ISDD: The Big Picture
eXpress
History &
Feedback
Module
DSI
Workbench
Third-party
Test Executive
Simulation-Based
Trade Studies,
Presentation-Ready
Graphics
Relational
Database
Maintenance
Module
FTA
Module
eXpress
Design Viewer
(freeware)
DSI Embedded
Reasoner
RTAT
Health Management
Platform, ATE. etc.
DSI Dynamic
Reasoner
Dynamic
Diagnostics
Module
eXpressML
Module
Other Industry Formats
eXpressML
Proprietary DSI Formats
Tight Integration
Interoperability
DiagML
Diagnostic Analysis
& Reports
Third-Party
Diagnostic Executive
Design
Import
Manager
MBSE data,
SYSML, etc.
Empirical
Data
Prognostics
Module
DFI
Design Viewer
Redline Module
with TestDRIVE
with TestDRIVE
DASH
TRD
Module
© 2021 DSI International
Sneak Path
Analysis
Module
with TestDRIVE
ISDD
AT-Easy
D-Matrix
Special Purpose Export Modules

6. 6
XXI century system architecture evolution
Risks:
 Potential failures
 Time to restart
Availability
System architecture complexity still increasing
• System of Systems
• Distributed Systems
Systems are evolving
• Upgrades / Changes
Time to Market decreases

7. 7
Different tests domains for one system
Design : validates that the system
meets the requirements
Depending on system lifecycle phases, test objectives and characteristics are different,
Maintenance : validates that the
system is functional and identifies
faulty elements
Production : validates that the
produced system complies definition
and is functional
System design
Detailed design Integration tests
System VV tests
Production Maintenance
Production
Production
Maintenance
months/year years /decades
hours/days

8. 8
Definition – system characteristic
The “testability ” of a component […] can be defined by its aptitude to be tested so that manufacturer, Defense user and those who will be in charge to
perform the maintenance can:
 Detect its failures
 Validate its performance and it operational status
 Identify failure root causes
 Perform maintenance actions
Within reasonable cost and period.
GAM T 16 A (1993)
“ Testability ” defines a characteristic of design that allows the operational status of an entity and the location of faulty replaceable components within that
entity, to be confidently determined in a timely and cost effective manner.
Operational status can mean operable, partly operable and inoperable. It should be noted that this definition is applicable to a system that comprises of one or
more of the following elements: electrical, electronic, mechanical, and software.
NATO STANAG 4428 issue 1

9. 9
Operational
need
Need
Analysis
Functional
Architecture
Physical
architecture
Critical system
Diagnosis & Prognosis
embedded
Environment
Operational & Support
Test
definition
Diagnostic
(Development and
Reports)
E s t i m a t e d
r e l i a b i l i t y
S a f e t y
a s s e s s m e n t
F M E C A * *
M a i n t a i n a b i l
i t y
& L S A *
M a i n t e n a n c e
p r o c e s s
S Y S T E M E N G I N E E R I N G R E L I A B I L I T Y & S A F E T Y M A I N T E N A B I L I T Y & L S A T E S T A B I L I T Y
1 2 3 4
*LSA = Logistic Support Analysis
** FMECA = Failure Modes, Effects & Criticality Analysis
Complementary Engineering domains

10. 10
Different consistent engineering process & frameworks
Model Based System Engineering
Model Based Testing
Model Based Safety Assessment
M.B.S.E M.B.S.A
M.B.T
Each domains has its own specific optimized
frameworks based on years of practice
Harmony
All4Tec
SCXML
ATML
M.B.P.S
Model Based Product Support
OPUS10

11. 11
Different yet consistent engineering processes
MBSE
Function & Parts
MBSA
Dysfunction
Reference
MBT
Test
Reference Reference
Consistency
Logistic Support
Ensure
Prevent
Are used by
MBPS

12. 12
Different Meta models
MBSE
MBSA
MBSE
MBSA
ENUM
abstract
Legend
Consistency analysis on Meta models

13. 13
Operational
need
Need
Analysis
Functional
Architecture
Physical
architecture
Critical system
Diagnosis & Prognosis
embedded
Environment
Operational & Support
S Y S T E M E N G I N E E R I N G
1 2 3 4
*LSA = Logistic Support Analysis
** FMECA = Failure Modes, Effects & Criticality Analysis
Complementary Engineering domains

14. 14
Critical system example : railway crossing

15. 15
Operational
need
Need
Analysis
Functional
Architecture
Physical
architecture
Critical system
Diagnosis & Prognosis
embedded
Environment
Operational & Support
E s t i m a t e d
r e l i a b i l i t y
S Y S T E M E N G I N E E R I N G R E L I A B I L I T Y & S A F E T Y
1 2 3 4
*LSA = Logistic Support Analysis
** FMECA = Failure Modes, Effects & Criticality Analysis
Complementary Engineering domains

16. 16
System Engineering with preliminary RAMS
New viewpoint for Capella:
RAMS
Aims:
o allow System Engineers to add information about Reliability in
their usual framework and formalism,
o Allow feedbacks from maintenance operators
o Connector between MBSE and MBSA

17. 17
LINK with MCO: Virtual optimization loop
Maintenance Operator
System & Safety Engineer System modeling & Reliability
On-board sensors
Monitoring module
REX
Algorithms
Field data
FPT
Models Update

18. 18
CAPELLA module : RAMS
Ability to define Failure mode for a function
Functional mode Deterministic transition
Failure mode Stochastic transition

19. 19
Failure mode and stochastic transition

20. 20
Link between System Engineering and Safety Assessment
Addition of Measurement & Hazardous Event

21. 21
Operational
need
Need
Analysis
Functional
Architecture
Physical
architecture
Critical system
Diagnosis & Prognosis
embedded
Environment
Operational & Support
Test
definition
Diagnostic
(Development
and Reports)
E s t i m a t e d
r e l i a b i l i t y
S a f e t y
a s s e s s m e n t
F M E C A * *
S Y S T E M E N G I N E E R I N G R E L I A B I L I T Y & S A F E T Y M A I N T E N A B I L I T Y & L S A T E S T A B I L I T Y
1 2 3 4
*LSA = Logistic Support Analysis
** FMECA = Failure Modes, Effects & Criticality Analysis
Complementary Engineering domains

22. 22
eXpress tool domains
System design
Test definition & characteristic
Failure mode & effect definition
FMECA analysis
MBSA
Testability analysis
MBT

23. 23
EXPRESS deliverables : RAMS
o Reliability (MTBF)
o Availability (intrinsic)
o Maintainability (MTTI,MTTR)
o Safety (FMEA, FTA)
o Detection performance
o Diagnosis performance

24. 24
Diagnostic: fault tree localization implementation
Isolation
Fault Procedure Tree optimized
according to criteria:
o Fault detection duration
o Fault detection cost
o Number of test
o Reduce intrusiveness
o Proof operational status
o Custom rules…
System Auto Test
Optimized diagnostic procedures

25. 25
Critical system example : railway crossing
Digital thread
Capella to eXpress
Safety Assessment
&
Testability analysis
Improvement
&
Capella loopback

26. 26
Operational
need
Need
Analysis
Functional
Architecture
Physical
architecture
Critical system
Diagnosis & Prognosis
embedded
Environment
Operational & Support
Test
definition
Diagnostic
(Development
and Reports)
E s t i m a t e d
r e l i a b i l i t y
S a f e t y
a s s e s s m e n t
F M E C A * *
M a i n t e n a b i l
i t y
& L S A *
M a i n t e n a n c e
p r o c e s s
S Y S T E M E N G I N E E R I N G R E L I A B I L I T Y & S A F E T Y M A I N T E N A B I L I T Y & L S A T E S T A B I L I T Y
1 2 3 4
*LSA = Logistic Support Analysis
** FMECA = Failure Modes, Effects & Criticality Analysis
Complementary Engineering domains

27. 27
MBPS - Logistic support analysis
Modeling of logistic support combined with reliability and maintainability data allow computation of global
logistic support cost.

28. 28
Global optimization
System Design, Testability, Logistic Support organization ,… changes impact can be simulated for global
optimization
System Design & Testability collaboration to allow
evolution from Black Box LRU to White Box LRU + SRU
with diagnostic capability
=> Global cost optimization
Logistic Support & Testability collaboration to allow
near field repair for defective LRUs
=> System Availability optimization at
constant budget

29. 29
Systems of systems modeling
• A modeling and hierarchical study for a global
collaborative design,
• “Black box” subsystems for IP issues,
• a global performance study via a System of
Systems vision integrated in an industrial
organization.
The collaborative MB framework allows to manage :
Design
Information
Repository
RAMS
Information
Data Bases
System
Engineering Tool
Workbench
Framework
Data
Information
Model
Patterns
…
…
EQUIPMENT
SUB SYSTEM
SYSTEM
-n
-n
-n
-n
Top Down
Bottom Up
Model Processing
 Consistency check
 Completeness check
 Scenario simulations
SoS Analysis Reports
Detection
Diagnostic
Analysis
S a f e t y
a s s e s s m e n t
M a i n t e n a n c e
A n a l y s i s

30. 30
Collaborative Model Based Engineering for
optimization
System Engineering
CAPELLA
Reliability &
Safety assessment
eXpress
Testability analysis
eXpress
Export
/
Import
feedback
RAMS
data
Operational support &
Optimized Support
Means
Logistical support analysis
OPUS10
Collaborative Model Based Engineering in design
phases is a key enabler for optimization of system and
it’s support.
RAMS
VP

31. 31
Questions & Contacts
SPHEREA
testability@spherea.com
DSI
info@dsiintl.com

32. 32
FOCUSED ON YOUR CRITICAL
SYSTEMS