Rolls-Royce is a pre-eminent engineering company focused on world-class power and propulsion systems. This webinar will discuss how Rolls-Royce is using Arcadia / Capella to define the architecture of a large civil aerospace turbofan engine. MBSE promises to help manage system complexity and minimise the associated risk. This webinar was driven by Jim Daly: Jim Daly has nearly forty years’ experience in aerospace engine development: fuel systems; control systems; software development; process improvement and thirteen years in current role as a System Architect at Rolls-Royce, responsible for control system and whole engine architecture and since 2016 deployment of MBSE.

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Using Capella for large complex mechanical systems – a pilot study
Jim Daly, Whole Engine System Architect, CEng MRAeS.
09 April 2019
The informationin this document is proprietary and confidential to Rolls-Royceand is available to authorised recipients only – copying
and onward distribution is prohibited
Country Classification Date
UK Not listed 09 April 2019

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▪ Agenda
▪ Turbofan engine architecture
▪ Application of Arcadia/Capella
▪ Q & A

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MBSE Pilot Study -
Ultrafan® Power
Gearbox (PGB) Oil
System
▪ Objectives - (Deliverables):
▪ System architecture for PGB
Oil System
▪ Integrated requirements.
▪ Integration with Safety
process – ARP4754A
compliant
. https://www.rolls-royce.com/~/media/Files/R/Rolls-Royce/documents/civil-aerospace-downloads/High-Res-posters/high_res_ultrafan.pdf

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MBSE Pilot Study -
Ultrafan® Power
Gearbox (PGB) Oil
System
▪ Objectives - (Deliverables):
▪ System architecture for PGB
Oil System
▪ Integrated requirements.
▪ Integration with Safety
process – ARP4754A
compliant
.
https://www.rolls-royce.com/~/media/Files/R/Rolls-Royce/documents/civil-aerospace-downloads/High-Res-posters/high_res_ultrafan.pdf
Sub-
system A
Sub-
system B
Sub-
system C
Multiple interactions
with diverse systems

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Architectural de-
composition
▪ Need a model or models that: -
▪ Captures interactions
across system boundaries
▪ Not sequential
▪ Maximise design space
▪ Allows for iteration of
design decisions
Turbo-Fan
Engine
Oil system
Sub-system 1
Sub-system 4Sub-system 3
Sub-system N
Sub-system 4.1 Sub-system 4.2
https://www.rolls-
royce.com/products-and-
services/civil-aerospace/future-
products.aspx#section-overview
Nacelle ( Intake, TRU,
Cold Nozzle etc.)
Propulsion
System (x2 ‘Power Plant’)
Other
Aircraft Sub-
Systems
https://utcaerospacesystems.
com/product_gallery/nacelle
-systems/
Sub-system 2

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Architectural de-
composition
Other
Aircraft
systems▪ A Federated model, to
capture and analyse the
complete architectural
hierarchy.
▪ Each model defining a
system architecture
▪ Capella sub-system
transition Plug-in
Sub-system 3Sub-system 1 Sub-system N
Sub-system 2
Oil System Sub-system 5
Sub-systems
………
https://utcaerospacesystems.
com/product_gallery/nacelle
-systems/
http://www.polarsys.org/capella/images/features/
transition_system_subsystem.png

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Capturing Emergent
Behaviour?
Sub-system
Transition
▪ By unconstrained
functional and system
modelling at the : -
▪ System Analysis
▪ Logical
Architecture
▪ Physical
Architecture
Oil System
Model
New: -
Functions,
Actor systems,
Interactions

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Iterative system
development?
Other
Aircraft
systems
Sub-system 3Sub-system 1 Sub-system N
Sub-system 2
Oil System Sub-system 5
Sub-systems
………
https://utcaerospacesystems.
com/product_gallery/nacelle
-systems/
http://www.polarsys.org/capella/images/features/
transition_system_subsystem.png

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1.1 Ideal PA View + Emergent Functions view
+
Iterative system
development?
▪ Ideal ‘prime’ functions
transitioned to Sub-system
from Whole Engine PA
Turbofan Engine Model
1. Ideal PA view
Sub-
system 5
Sub-
system 1
Sub-
system 4
Sub-
system N
▪ Additional Sub-system
Functionality, to deal with
emergent behaviour,
Identified & iterated back up
to create 2nd PA view
▪ Sub-system emergent
functions allocated to
emergent systems and
transitioned to dedicated
models
▪ New Sub-system interactions
(and associated Functions)
identified & iterated back up
to be included in WE model
to become definitive PA view.
Emergent
Sub-system
+
1.1.1 Ideal PA + Emergent Functions + Emergent System view
Multiple sequential PA Views to capture iterative system development!

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N.1 Dedicated O/S View + Emergent Functions view
+
Iterative system
development –
Whole Engine Model
N. Dedicated O/S view
Sub-
system 5
Sub-
system 1
Sub-
system 4
Sub-
system N
Emergent
Sub-system
+
N.1.1 Dedicated + Emergent Functions + Emergent System view
▪ CS-E 510
▪ (2) The following effects
must be regarded as
hazardous Engine
Effects:
(i) Non-containment of
high-energy debris,
Dedicated PA Views to capture event driven functionality

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System architecture
definition
▪ Objectives - (Deliverables):
▪ System architecture for PGB
Oil System
▪ Integrated requirements.
▪ Integration with Safety
process – ARP4754A
compliant
.
▪ Federated model – Sub-system transition Plug-in
▪ Emergent behaviour – Unconstrained addition of Functions,
systems, exchanges across the SA-LA-PA
▪ Iterative system development – Multiple PA views.

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Requirements
integration
▪ Objectives - (Deliverables):
▪ System architecture for PGB Oil
System
▪ Integrated requirements.
▪ Integration with Safety process –
ARP4754A compliant
▪ PVMT Plug-in
.

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Requirements
integration
▪ Objectives - (Deliverables):
▪ System architecture for PGB Oil
System
▪ Integrated requirements.
▪ Integration with Safety process –
ARP4754A compliant
▪ PVMT Plug-in
.

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Requirements
integration
Validation (analytical
analysis e.g. Simulink)
▪ Objectives - (Deliverables):
▪ System architecture for PGB Oil
System
▪ Integrated requirements.
▪ Integration with Safety process –
ARP4754A compliant
▪ PVMT Plug-in
.

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Requirements
integration
Capella <-> DOORS Integration
▪ In the short term, and
for some legacy
projects, linkage
between Capella and
DOORS
▪ Capella <-> DOORS
Plug-in (RR)

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To be continued………….
Integration with
Safety
▪ Objectives - (Deliverables):
▪ System architecture for PGB
Oil System
▪ Integrated requirements.
▪ Integration with Safety
process – ARP4754A
compliant
.

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Further
development
topics
▪ Full integration with Safety process
▪ Model data exchange – SysML Import/export
▪ Integration with Mathworks Simulink
▪ Integration of Trade Studies
▪ Variants (libraries)

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▪ Q & A ….