Transcript 2007 Complex System Engineering Jussieu PARIS 7

Introduction to
Complex System Engineering
Emmanuel FUCHS
Slides available soon at www.elfuchs.fr
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Complex
System
Examples
Information Systems
System
Problems
Examples
System Problems Examples
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
System definition
(Eberhardt Rechtin 1926-2006)
• A system is a construct or collection of different elements that
together produce results not obtainable by the elements alone.
• The elements, or parts, can include people, hardware, software,
facilities, policies, and documents; that is, all things required to
produce systems-level results.
• The results include system level qualities, properties, characteristics,
functions, behavior and performance.
• The value added by the system as a whole, beyond that contributed
independently by the parts, is primarily created by the relationship
among the parts; that is, how they are interconnected.
Systemic
The whole is greater than the
sum of the parts;
The part is greater than a
fraction of the whole.
Aristotle
System: another definition
• A system is any set (group) of interdependent or
temporally interacting parts.
• Parts are generally systems themselves and are
composed of other parts, just as systems are
generally parts of other systems.
System Definition
Mission
System
Users
Sub
System
Border
Sub
System
Sub
System
Stakeholders
Environment
System
Meta
Model
operates In
Context
operates In
Purpose
has a
Interacts with via item
External
System
System
performs
has a
performs
built from
performs
receive, transform, sends
Components
Life Cycle
performs
Functions
has
carries
Items
Energy
Physical
Entity
Interfaces
Information
Entity
From INCOSE
SE Bodies
• http://www.afis.fr/
– Association Française d'Ingénierie Système
• http://www.incose.org/
– International Council on Systems Engineering
(INCOSE)
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
System Engineering Definition
“an interdisciplinary approach
encompassing the entire technical effort to
evolve and verify an integrated and
balanced set of system, people, product,
and process solutions that satisfy
customer needs…..”
System Engineering (SE)
• SE focuses on defining customer needs and required
functionality early in the development cycle,
documenting requirements, then proceeding with design
synthesis and system validation while considering the
complete problem
• Systems engineers deal with abstract systems, and rely
on other engineering disciplines to design and deliver the
tangible products that are the realization of those
systems.
• Systems engineering effort spans the whole system
lifecycle.
Systemic Approach
• One + One > two
• Aristotle : The whole is more than the sum
of its parts.
– Parts (Components)
– Connections
System Engineering Meta Model
required for
End
Product
operates in
Operational
Environment
focus on
must be on
Stackholders
expectations
focus on
maintains vision on
define in term of
System
Engineering
is a
focus on
Enabling
Products
performed by
balance in
Costs
Schedule
Performances
Structured
Discover
Process
Team
From INCOSE
System engineer/architect
• Works with system abstraction.
– It is impossible to master everything
• Requirements Management
• System Model
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Design the right system
As proposed by
the project sponsor
As specified in the
project request
As designed by
the project analyst
As proposed by
the programmers
As installed at
the users’ site
What the customer
really want
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Process Definition
• Set of interrelated of interacting activities
which transforms inputs to outputs
Inputs
Outputs
P
A Process
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
Process: V cycle
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
Sequential V cycle drawbacks
Documentation
And mock-up
Phase
Sequential V cycle drawbacks
Documentation
And mock-up
Phase
Iterative and Incremental
Iterative
Incremental
Barry W.
Boehm
Iterative and Incremental
• The Systems Engineering Process is not
sequential. It is parallel and iterative.
• The complex interrelationship between creating
and improving models throughout the process of
developing and selecting alternatives is a good
example of the dynamic nature of the systems
engineering process.
Process Standardization
• NASA
• DOD (US Departement Of Defense):
– Documentation Model
• IEEE
• ISO (International Organization for
Standardization)
• IEC (International Electrotechnical Committee).
– ISO/IEC 15504 / SPICE (Software Process
Improvement and Capability dEtermination)
• SEI (Software Engineering Institute)
Capability Maturity Model Integration
• CMMI defines the essential elements of effective
processes for engineering disciplines based on best
industry experiences.
• CMMI models provide guidance when developing and
evaluating processes.
• CMMI models are not actually processes or process
descriptions.
CMMI Maturity Levels
Level
Identified as
Status
5
optimizing
focus on process improvement
4
quantitatively
managed
process measured and controlled
defined
process characterized for the organization
and is proactive
managed
process characterized by projects and often
reactive
initial
process uncontrolled poorly managed and
reactive
3
2
1
Process Documentation and Review
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SSS: System/Segment Specification
SSDD : System/Segment Design Document
IRS : Interface Requirement Specification
ICD : Interface Control Definition
• SRR : System Requirement Review
• SDR : System Design Review
• TRR : Test Readiness Review
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Process Activities
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
What is a requirement ?
• A requirement is a condition to be satisfied
in order to respond to:
– A contract
– A standard
– A specification
– Any other document and / or model imposed.
Requirements
• User’s Requirements
– Statements in natural language of the system
services.
– Described by the user
• System Requirements
– Structured document setting out detailed
description of system services.
– Part of the contract
User’s Requirements example
• A customer must be able to abort a transaction in
progress by pressing the Cancel key instead of
responding to a request from the machine.
• The washing machine will be used in the following
countries: UK, USA, Europe, Eastern Europe
Process
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
System Requirements
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The System shall provide ........
The System shall be capable of ........
The System shall weigh ........
The Subsystem #1 shall provide ........
The Subsystem #2 shall interface with .....
Requirement Quality
• A good requirement states something that
is necessary, verifiable, and attainable
• To be verifiable, the requirement must
state something that can be verified by:
– analysis, inspection, test, or demonstration
(AIDT)
Requirement analysis
• User Requirement
– Minimum levels of noise and vibration
are desirable.
• System Requirement
– Requirement 03320: The noise
generated shall not exceed 60 db
Requirement Types
• Functional requirements
– Functional requirements capture the intended
behavior of the system.
– This behavior may be expressed as services,
tasks or functions the system is required to
perform
• Non-Functional requirements
– All others
• Constraints
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Process
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
System Architecture
• The System Architecture identifies all the products
(including enabling products) that are necessary to
support the system and, by implication, the processes
necessary for development, production/construction,
deployment, operations, support, disposal, training, and
verification
Architecture Modeling
• System : Abstraction
– Functional model
– Dynamic model
– Semantic Model
– Object model
– Physical Model
– Interfaces Model
• Model Views
Architecture
Meta Model
Mission
1..*
fullfil
influence
Environnement
system
Has a
Architecture
Is part of
has a
1..*
Described by
identify
Is important for
*
1..*
stakeHolder
i
1
Is addressed by
identify
1..*
a
a
1..*
Used to cover
1
rational
participates
in
select
1..*
concerns
provides
Architecture
description
1..*
Organised in
View
Points
1..*
views
Conform to
1..*
1..*
Participate in
consist off
Has sources
From IEEE
0..1
View Points
Library
aggregates
1..*
1..*
Established method for
1..*
model
Architecture and Components
Assembly
system
has
Architecture
define
use
has
connections
component
0..*
2
Is connected to
Example of Architecture Views
• The Functional Architecture
– identifies and structures the allocated
functional and performance requirements.
• The Physical Architecture
– depicts the system product by showing how it
is broken down into subsystems and
components
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Functional To Physical Model
• Functional : Discover the system functions
• Washing Machine
– What it does ?
• Washes
– How it does ?
• Agitates
– Physical Component : Agitator
Functional VS physical Model
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How to fly ?
Look at birds: Physical Model
So I need: Legs, Eyes, Brain, and Wings.
But I can not fly !!!
Why ?
I have to find the flight functional model !
Flying functional model
• Functional decomposition of flying
function:
– Produce horizontal thrust,
– Produce vertical lift.
– Takeoff and land,
– Sense position and velocity,
– Navigate,
Example Birds physical for flying
• Physical decomposition:
– physical components that birds used to fly:
Legs, Eyes, Brain, and Wings.
• But can not be applied to system directly
Bird and Airplane
Functional to Physical architecture
mapping
Function
Airplane Physical
Component
Bird Physical
Component
Takeoff and land
Wheels,
Legs
Sense position and
velocity
Vision or radar
Eyes
Navigate
Brain or computer
Brain
Produce horizontal
thrust
Propeller or jet
Wings
Produce vertical lift
Wings
Wings
Multi-criteria decision
Trade Off
• Multi-criteria decision-aiding techniques
are available to help discover the preferred
alternatives.
• This analysis should be repeated, as
better data becomes available.
Washing Machine example
Context Diagram
Dirty Cloths
Cold H2O
Washing
Clean Dump Cloths
Soap
Electricity
Operator Settings
Machine
Dirty Hot H2O
Washing Machine Functional Breakdown
Washing
machine
Washing
supply
rinsing
wringing
agitating
draining
Washing Machine Data Flows
power
heating
dirty clothes
agitating
holding
clean clothes
Clean water
supplying
Soap
draining
Dirty water
Washing Machine Physical Model
agitator
plungers
tube
draining
hand-operated washer
Washing Machine Physical Model
agitator
US
top loading
Outer tube
draining
Washing Machine Physical Model
Washing
Machine
Electrical
SubSystem
Drive Motor
Sequence
SubSystem
Mechanical
SubSystem
Heating
Resistor
valve
Liquid
SubSystem
drawer
top loading
Agitator
Inner tube
Outer tube
pump
Washing Machine Physical Model
Inner tube = drum
Outer tube
agitator
draining
front loading
Europe
Washing Machine Physical Model
Washing
Machine
Electrical
SubSystem
Drive Motor
Sequence
SubSystem
Mechanical
SubSystem
Heating
Resistor
Liquid
SubSystem
Drum
front loading
valve
drawer
tube
pump
Washing Machine Physical Model
power
driving
motor
dirty clothes
drum
front loading
clean clothes
Clean water
drawer
Soap
tube
pump
Dirty water
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Process
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
Integration
• Integration means bringing things together
so they work as a whole.
Spaghetti Plate Syndrome
System
System Integrator
Architect
Spaghetti Plate
Encapsulation Analogy
A driver doesn't care of
engine's internal working.
He only knows the interface
Implementation
Interface
Content
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Complex System Example
System Definition
System Engineering
Design The Right System
Process
Requirements
Design and Architecture
Physical Decomposition
Integration
IVVQCA
Process
User
Requirement
Analysis
System
Verfication
System
Requirement
Analysis
System
Validation
System
Integration
System
Design
Components
Components
Components
Developpment
Components
Developpment
Developpment
Developpment
IVVQCA
• Integrate :
– Build the system
• Verification :
– Ensures that you built it right
• Validation :
– Ensures that you built the right thing
• Certification :
– Ensure that the system is safe
• Acceptance :
– Ensures that the customer gets what he wants and
the company get paid.
Ensure that the system is safe
Conclusion
Thank You For Your Attention
Questions are welcome
Contacts :
[email protected]
Slides Available soon at www.elfuchs.fr